These are the required measurements of a sukkah: Its height - I.e., the height of its inner space, without including the height of the s'chach (Eruvin 3b)

should not be less than ten handbreadths - anything less is not considered to be a dwelling fit for human habitation (See Sukkah 4a.) Sukkah 4b-5a derives the concept as follows: The ark and the kaporet covering it were ten handbreadths high. This constituted a line of demarcation between the place where the Shechinah was manifest and the area below it. Thus, we see that a height of ten handbreadths is sufficient for an independent area.

Rabbenu Manoach establishes a closer relationship between the above concept and a sukkah, noting that Exodus 25:20 describes how the wings of the cherubs "shall shield the kaporet," using the verb סככים, which has the same root as the word s'chach. The beginning of the height of the cherub's "shield," ten cubits, is the minimum of the height for our s'chach.

nor more than twenty cubits. - Any structure more than twenty cubits high can only be built as a permanent dwelling. Hence, it is unfit to serve as a sukkah, which must be of a temporary nature. (See Sukkah 2a and the Rambam's commentary on the Mishnah.)[ It must be noted that any structure less than 20 cubits high can serve as a sukkah even if its walls are of a permanent nature.]

A cubit is 48 centimeters according to Shiurei Torah and 57.6 centimeters according to the Chazon Ish.

Its area should not be less than seven handbreadths by seven handbreadths. - the minimum size necessary to contain a person's head, the majority of his body [6 handbreadths by six handbreadths], and a small table [a handbreadth by a handbreadth] (Jerusalem Talmud, Sukkah 2:8). A handbreadth is 8 centimeters according to Shiurei Torah, and 9.6 centimeters according to the Chazon Ish.

The Rambam explains the requirement of seven handbreadths by seven hand breadths as follows: The first three hand breadths are not of consequence because of the principle of l'vud and four additional handbreadths are required since the smallest area of halachic consequence is four cubits by four cubits (Commentary, to the Mishnah, Sukkah 1:1).

If the sukkah is not seven handbreadths in either length or width, it is invalid, even if its area equals 49 square handbreadths. If it is round in shape, it must be sufficiently large to encompass a square seven by seven (See Halachah 7). This size is required because if either of the dimensions were less, it would not be considered a dwelling fit for human habitation (Shulchan Aruch, Orach Chayim 634:1-2; Magen Avraham; Taz).

[There is no maximum limit to] its area - The commentaries point to Sukkah 27b: "All Israel is fit to sit in one sukkah," as the source for this statement. A sukkah large enough to contain "all Israel" must possess a sizable area.

and one may increase it [to include] a number of millim. - A mil is approximately a kilometer in contemporary measure.

A sukkah which - does not meet the above requirements and

is less than ten handbreadths high, smaller than seven handbreadths by seven handbreadths in area, or taller than twenty cubits - The Shulchan Aruch (Orach Chayim 633:2-5) mentions a number of techniques by which a sukkah of this size can be made kosher, by decreasing the height of its inner space.

even [if the increase or decrease] is of the slightest amount - is invalid.

A sukkah which does not possess three walls is invalid. - Though Sukkah 6b mentions Rabbi Shimeon's opinion, which requires four walls, all authorities accept the more lenient view. The Jerusalem Talmud (Sukkah 1:1) explains that their difference of opinion is based on the exegesis of Isaiah 4:6:

There will be a sukkah that will serve as a shadow from the heat during the day, a place of refuge, and a cover from storm and from rain.

The Sages maintain that the verse refers to three different activities, and hence require three walls. Rabbi Shimeon counts "a cover from storm and from rain" as two different activities, and hence requires four walls.

However, if it has two complete walls - i.e., walls of at least seven handbreadths long, so that the minimum requirements for the sukkah's area mentioned in the previous halachah can be met

perpendicular to each other in the shape of [the Greek letter], gamma - Rabbenu Manoach notes that a gamma has the same shape as the Hebrew letter dalet (see accompanying drawing) and asks why the Sages did not use that letter to refer to the intended shape. He explains that the very letters of the Hebrew alphabet are endowed with holiness. Hence, the Sages did not want to use them as an example to refer to a mundane matter.

it is sufficient to construct a third wall that is [only] slightly more than a handbreadth wide and place it within three handbreadths - Sukkah 16b teaches that whenever there is a gap of three handbreadths or less between two entities, the principle of l'vud applies. The gap is considered to be closed and the two parts connected. Thus, the third wall is considered to be more than four handbreadths long, hence spanning more than half of the length required for the third wall. Therefore, it is acceptable (Rabbenu Nissim).

of one of the two walls. - See the accompanying diagram.

The Rabbis have posed an abstract question: Is the minimum requirement for a sukkah three walls (including one which is incomplete), or must a sukkah have four walls, however, the Torah was lenient enough to consider a sukkah of this nature as comparable to one of four walls.

The Marcheshet brings support for the latter view, quoting Sukkah 7b, which states that since the third wall only a handbreadth in size is considered to be a wall with regard to the laws of sukkah, it is also considered to be a wall with regard to the laws regarding a private domain on the Sabbath. In the latter instance, four walls are necessary.

Also, one must construct the likeness of an entrance - to complete this third wall. This is necessary...

since it - the sukkah

does not possess three complete walls. - However, if the three walls are complete - i.e., at least seven handbreadths in length - as in the accompanying diagram, no "likeness of an entrance" is required.

The Bayit Chadash (Shulchan Aruch, Orach Chayim 430) explains that the requirement of a "likeness of an entrance" is a Rabbinic ordinance, and, according to Torah law, a sukkah is acceptable as long as the third wall is a handbreadth as required.

We have already explained in Hilchot Shabbat - 16:19

that wherever the term "a likeness of an entrance" is used, it may be a rod on one side, another rod on the opposite side, and a third above - The Ramah (Shulchan Aruch, Orach Chayim 630:2) states that if the two rods reach the s'chach, a third rod is unnecessary. (See Mishnah Berurah 630:12.)

even though it does not touch them. - as depicted on page 67.

If the two walls - each being seven handbreadths or more long

were parallel to each other and there was an open space between them, one should construct a wall slightly more than four handbreadths wide - as depicted in the accompanying diagram.

Since the two walls are not connected, the third wall which "connects" them must be longer (Sukkah 7a).

and place it within three handbreadths - so that it will be considered l'vud.

of one of the two walls; then, [the sukkah] is kosher. - The third wall is considered to be seven cubits long itself - the four cubits of actual length and the three cubits between it and the wall that are added to it, because of the principle of l'vud (Rambam, Commentary on the Mishnah, Sukkah 1:1).

However, it is necessary to construct "the likeness of an entrance" - between the wall of four handbreadths and the wall further removed from it.

This opinion is not universally accepted; and some authorities do not require a "likeness of an entrance" for such a sukkah. Nevertheless, the Shulchan Aruch (Orach Chayim 630:3) quotes the Rambam's opinion as halachah.

The Ramah mentions that the "likeness of an entrance" is required only when the third wall needs the principle of l'vud for it to be considered seven handbreadths long. However, if the wall is actually seven handbreadths or more long, nothing more is necessary.

If the rods of the s'chach of the sukkah extend beyond the sukkah and one wall extends with them, - As portrayed in the accompanying diagram, the sukkah has two walls, each at least seven handbreadths long, joined to each other at a right angle. The third wall is also joined to the other at a right angle; however, its length exceeds that of the wall opposite it, and thus, the fourth side of the sukkah, which remains open, slants at an angle.

they are considered to be [part of] the sukkah. - sitting under the extension is considered to be the same as sitting under the portion enclosed by three walls. (See Shulchan Aruch, Orach Chayim 631:7.)

Walls - at least seven handbreadths high

which are connected to the roof of the sukkah, but do not reach the earth - See accompanying diagram.

If they are more than three handbreadths above the earth, they are invalid - Sukkah 16a records a difference of opinion between the Sages whether a "hanging partition" - i.e., a partition that is not connected to the earth - is kosher. The halachah does not accept such a partition, because animals can crawl under it. (See Shabbat 97a.) Nevertheless...

if the distance is less than that - three handbreadths

they are kosher - Because of the principle of l'vud, it is considered as if they actually reach the ground.

[The following rules apply] should the walls be connected to the earth, without reaching the s'chach: - See the accompanying diagram.

If they are ten handbreadths high - they are considered to be a viable partition. Therefore...

they are kosher even though they are removed several cubits from the roof - We say גוד אסיק מחיצתא - "Pull up and raise the partition;" i.e., it is considered as if the partition has been extended upward and reaches the s'chach. See Sukkah 4b for an additional discussion of this concept.

Though this concept is accepted, we do not say מחיצתא גוד אחית - "Pull down and extend the partition." Hence, in the first clause of this halachah, the partition is not acceptable until it reaches three cubits of the ground.

[It is possible to distinguish between the two cases as follows. A partition on the ground that must be extended upward serves as a functional divider. In contrast, a partition hanging downward cannot adequately fulfill its purpose unless it reaches within three handbreadths of the ground. (See also the Or Sameach's resolution of a difficulty arising from Eruvin 79a.)]

provided they - the walls

are positioned below the end of the roof - i.e., the s'chach, so that the s'chach covers them.

Furthermore, the walls may even be slightly removed from the s'chach. (See Shulchan Aruch, Orach Chayim 630:9.)

If the roof - the s'chach

was separated from the wall by more than three handbreadths, it is invalid - for then the distance is too great for the s'chach to be considered the roof of these walls. In such an instance, not only is sitting under the open portion of no halachic import, the entire sukkah is invalid. Nevertheless, a sukkah in which the distance is...

less than this amount is kosher - because of the principle of l'vud. This concept also applies when the walls are as high as the s'chach. Even though the walls extend beyond the s'chach the sukkah is kosher. Nevertheless, one should not sit under the open portion.

If one suspended a partition which is slightly more than four handbreadths high at a distance of less than three handbreadths from the earth - and thus, it is viewed as connected to the earth because of the principle of l'vud.

and a distance of less than three handbreadths from the roof, - and thus, it is viewed as connected to the s'chach because of the principle of l'vud.

it is kosher. - Sukkah 16b explains that even though we must rely on the principle of l'vud twice, the sukkah is still kosher.

When a person constructs his sukkah among the trees - This halachah does not deal with the problem of the branches and leaves of the trees interfering with the s'chach. That issue is dealt with in Chapter 5, Halachah 12. Rabbenu Manoach and others have also raised questions whether the s'chach should be supported by the trees. (See the commentary on the following halachah.)

using the trees as walls, it is kosher if - the following two conditions are met

a) they are strong enough - by nature

or he tied them and reinforced them so that they would be strong enough - that they would not be shaken by the wind at all times; - even if the wind is not strong enough to uproot them, it should not cause them to sway back and forth

and b) he filled [the space] between the branches - this translation of the word אמיר is taken from Isaiah 17:6.

with hay and straw - weaving them together so that the wall would be a solid continuum (Sukkah 24b)

tying them - the hay and straw fillers

so that they will not be shaken by the wind.

[This is necessary,] for any partition that cannot stand before a normal - However, a sukkah's inability to stand before a hurricane wind does not invalidate it.

land wind - in contrast to sea winds, which are more powerful (Sukkah 23a)

is not considered to be a partition. - This law also has implications with regard to the Sabbath laws. (See Hilchot Shabbat 16:15, 24.)

If a person constructs his sukkah on top of a wagon - although the wagon moves and is not fixed in one place (Rashi, Sukkah 22b)

or on the deck of a ship - Sukkah 23a relates:

A person who constructs his sukkah on the deck of a ship: Rabban Gamliel deems it invalid; Rabbi Akiva deems it kosher.

Once Rabban Gamliel and Rabbi Akiva were traveling on a ship. Rabbi Akiva arose and constructed a sukkah on the ship's deck. The next morning, the wind came and blew it over. Rabban Gamliel asked Rabbi Akiva: "Akiva, where is your Sukkah?"

As apparent from the narrative, such a sukkah need not be strong enough to withstand sea winds. However, even according to Rabbi Akiva, it must be strong enough to withstand normal land winds, as explained in the previous halachah.

it is kosher, and one may ascend to it on the festival. - i.e., on the first day of Sukkot in Eretz Yisrael and on the first and second days in the diaspora.

If one constructs it on the treetops or on a camel's back, it is kosher - Sukkah 23a explains that Rabbi Yehudah objected to the use of such a sukkah, explaining that since it was not fit to be used on all seven days of the holiday (because of the prohibition against using it on the first day), it should not be used at all.

Our halachah follows Rabbi Meir's opinion. He accepts Rabbi Yehudah's motivating principle, but explains that in the case at hand, there is no inherent difficulty with using such a sukkah throughout the holiday. The only reason it is not used on the first day is an external factor - a Rabbinic decree - which should not affect the halachic status of the sukkah itself.

but one may not ascend to it on the festival - Surely, this prohibition also applies on the Sabbath.

From the Rambam's words, it appears that the restriction applies when the floor of the sukkah is actually in the tree. In contrast, Rashi (Shabbat 154b), Tosafot, Sukkah 22b and the Maggid Mishneh explain that even if the sukkah is on the ground and only the s'chach is supported by the tree, it is forbidden to use such a sukkah on the festival, lest one place utensils on the s'chach, and thus make use of the tree.

The Magen Avraham (628:6) quotes this opinion, but states that at present it is no longer customary to place articles on the s'chach. Therefore, it is permitted to use such a sukkah. His opinion is quoted by Shulchan Aruch HaRav 628:7, and the Mishnah Berurah 628:17, with one qualification. At the outset, it is desirable not to use an article as support for s'chach unless it is, itself, fit to be used as s'chach. Hence, since the trees themselves are not fit to be used as s'chach, they should not be used as its supports.

because climbing on a tree or animal is forbidden on a festival. - Beitzah 5:2 relates:

All the [prohibitions] which we are obligated [to observe as] sh'vut...on the Sabbath, we are obligated [to observe] on a festival. These are [the activities prohibited] as sh'vut: We do not climb a tree; we do not ride an animal...

In his commentary on that Mishnah, the Rambam writes:

"We do not climb a tree" - a decree lest we uproot [it];

"we do not ride an animal" - a decree lest we break off a branch to lead it.

If some of the walls were the result of human activity and some were trees, we consider [its structure]. We may ascend to any [sukkah] where, if the trees were taken away, it would be able to stand with the walls that were built by man alone. - The Rambam quotes this general principle from the Mishnah, Sukkah 23a. The Mishnah adds examples to express the concept more clearly:

Two [walls] that were the result of human activity and one [wall] from the tree, or two [walls] from the tree and one [wall] that is a result of human activity.

A sukkah that does not possess a roof is invalid - because a dwelling even of a temporary nature must have a roof.

To what does this refer? A sukkah whose walls are joined to each other like a hut - Rashi (Sukkah 19b) explains that this is a reference to a hunter's hut. See Diagram A;

alternatively, when the side of the sukkah is placed against the wall. - See Diagram B.

However, if it - the sukkah

has a roof, even only a handbreadth in width - between the two walls, as depicted in Diagram C. As long as it has a roof at least a handbreadth wide, the remainder of the roof may be slanted.

or if one lifted the side of the sukkah close to the wall a handbreadth above the ground - so that handbreadth is considered to be a wall, as depicted in the diagram below.

it is kosher. - for the fact that the roof is slanted does not disqualify the sukkah.

The Kessef Mishneh, Rabbenu Manoach, and others explain that though leniency is taken and such a sukkah is allowed, it must still possess all the dimensions required of a kosher sukkah mentioned in Halachah 1 of this chapter. Accordingly, at least six handbreadths of the slanted roof must itself be kosher for use as s'chach, and it must be more than 16 handbreadths long, so that it will be of the required height. When the Sukkah meets these qualifications, one is permitted to eat and sleep within it. (See also Ramah, Shulchan Aruch, Orach Chayim 631:10.)

A round sukkah - if its circumference is large enough to contain a square seven handbreadths by seven handbreadths, it is kosher even though it has no corners. - Sukkah 7b records an opinion which disqualifies such a sukkah because it is not fit for use as a permanent dwelling. Nevertheless, the halachah does not follow this view.

On this basis, we can understand the placement of this law. On the surface, it would be more appropriate to state this law as part of Halachah 1, which describes the dimensions of a sukkah. However, the Rambam structured the order of his halachot according to their motivating principles. Thus, the first clause of the halachah describes the construction of a sukkah whose shape causes it to be deemed unacceptable even as a temporary dwelling. In contrast, this clause describes a sukkah whose shape is abnormal, but acceptable for temporary purposes.

Should one place s'chach over an exedrah - A structure frequently employed in Roman architecture, and which was quite common in Jewish homes as well. There were a number of possible forms of this structure. Our halachah (in contrast to Hilchot Shabbat 17:35) deals with the following structure: A roof is placed between two walls, and within this roof a hollow place is left to allow sunlight to enter. Pillars are placed at each of the corners of the hole. The question is whether such a structure can serve as a sukkah if one placed s'chach over the hole. See diagram A.

which has projections [extending from its pillars] - At times these pillars were ornamented with artistic projections. See the diagrams below.

it is kosher, - Because of the projections, the opening of the ceiling is considered to be a third wall extending over the entire width of the exedrah and reaching the ground (Sukkah 18b) Thus, greater leniency is granted in this instance than in Halachah 3 of this chapter, where a partition four handbreadths in width is required.

Needless to say, as evident from Halachah 5:14, the walls of the exedrah cannot be more than four cubits removed from the s'chach.

regardless of whether the projections can be seen from the inside - of the Sukkah - although they cannot be seen from the outside - See diagram B.

or whether they can be seen from the outside - of the

Sukkah - although they cannot be seen from the inside. - See diagram C.

The Shulchan Aruch (Orach Chayim 630:8) quotes the Rambam's statements as halachah. However, the Ramah advises against constructing a sukkah in this manner.

If it - the sukkah constructed in the exedrah

does not have projections [extending from its pillars] - as explained in the previous halachah

it is not valid, because it resembles a sukkah constructed in an alley - which is described in Halachah 3.

because it has [walls on] only the two sides of the exedrah. The middle of the exedrah does not have a wall and there are no projections opposite it. - Hence, the principle that the opening of the roof is considered to be a third wall, reaching to the ground, is not applied in this instance. Rabbenu Manoach notes that different principles apply in this context from those in the laws of eruvin, but explains that there is a basic difference between the two contexts. Here, the two walls were not constructed for the sake of the sukkah. In contrast, in the laws of eruvin, the walls were constructed for the sake of creating an enclosure.

Should a person place s'chach over an alleyway which possesses a lechi - Hilchot Shabbat 17:2 states:

How is one permitted [to carry articles] in a closed alleyway?

One constructs a lechi (vertical pole) [at the entrance] to the fourth side or one lays a beam (korah) across [the span of the fourth side].

Rabbenu Manoach explains that although the alleyway is closed on three sides, were it not for the special provisions mentioned in this halachah, it would not be acceptable, because in this instance the s'chach is placed more than four cubits away from the end of the alleyway. Hence, generally, as explained in Chapter 5, Halachah 14, such a sukkah would not be acceptable.

or a well which possesses pasim, - Hilchot Shabbat 17:27 states:

When a total of eight pasim [partitions] are constructed around a well, two connected to each other at each of its corners, they are considered to be walls. Thus, even though on each side the open portion exceeds the closed, since the four corners are closed, it is permitted to fill up water from the well and to water an animal.

What is the height of each of these pasim? Ten handbreadths; their length must be at least six handbreadths and between each pas, there should be...no more than thirteen and one third cubits.

Thus, there are no complete walls to this structure, and without the special provision granted by this halachah, it would not be acceptable.

Sukkah 7b explains that each of these situations possesses an advantage over the other: The alley possesses an advantage in that it has two complete walls. In contrast, the well possesses an advantage in that it has partitions of some sort on each of its four sides. Hence, it is necessary to state both these laws, and neither could be derived from the other.

it is considered a kosher sukkah only on the Sabbath of the festival - The Tzafenat Paneach explains this as applying only to the days which precede the Sabbath. However, once the sukkah is acceptable on the Sabbath, it is also deemed kosher for the remaining days of the festival. (This view is not accepted by other authorities.)

Since this lechi and these pasim are considered to be partitions with regard to the Sabbath laws - On the Sabbath, one is allowed to carry only within an enclosed domain. Since the situations mentioned in this halachah are not actual enclosures and achieve that status only because of a Rabbinic ordinance, the application of these principles is confined to the Sabbath itself. Thus, on the Sabbath...

they are also considered to be partitions with regard to the laws of sukkah - and the sukkah is considered to be enclosed by three walls as required. However, throughout the remainder of the holiday, when the Rabbinic ordinances are not in effect, they are not considered to be enclosed structures. Hence, they are not acceptable as a sukkah.

The Shulchan Aruch (Orach Chayim 630:7) quotes these laws as halachah. (Also see the Ramah's notes.)

Should a person implant four poles in the four corners of the roof and place s'chach upon them - See the accompanying diagram.

it is kosher. Since he placed the s'chach [above] the edge of the roof, we consider that the lower walls ascend to the edge of the s'chach - because of the principle of גוד אסיק מחיצתא, it is considered as if the walls of the house have been extended upward, as explained in Halachah 5.

This halachah is based on the statements of Sukkah 4b. There are differences in the versions of the relevant passage possessed by the Rambam and Rav Sherirah Gaon, on the one hand, and those possessed by other Sages, on the other hand. Because of those textual differences, the Ra'avad, Rabbenu Manoach, and others have questioned the Rambam's decision. (See Maggid Mishneh.)

These differences caused the Shulchan Aruch (Orach Chayim 630:6) to reject the Rambam's decision. The Mishnah Berurah 630:31 states that even according to the Rambam, the poles must be placed exactly at the edge of the roof. If they are placed further in, even when they are within three handbreadths of the edge, the sukkah is not acceptable.

A sukkah which has many entrances and many windows in its walls is kosher even though the open portion - Any open portion less than three handbreadths in length is considered to be closed, based on the principle of l'vud (Hilchot Shabbat 16:17). The Magen Avraham 630:1 explains that regarding the laws of sukkah, this principle applies only when one constructs four walls. However, if the sukkah has only three walls, the principle of l'vud cannot be applied, to consider spaces less than three handbreadths in length to be closed.

exceeds the closed portion, provided there is no opening larger than ten cubits. - Sukkah 7a states:

[The laws governing] a wall of a sukkah resemble [those governing] the wall [of an enclosure] on the Sabbath...There is an additional [stringency to the laws] of the Sabbath that does not apply to a sukkah. On the Sabbath, [a wall] is permitted only when the enclosed portion is greater than the open portion. This does not apply to a sukkah.

The Rambam describes the laws governing a wall on the Sabbath as follows (Hilchot Shabbat 16:16):

Every wall whose open portion exceeds its enclosed portion is not considered to be a wall. However, if the open portion is equal to the closed portion, it is permitted, provided that none of the open portions exceeds ten cubits.

Based on the above, the Maggid Mishneh and the Kessef Mishneh explain that just as concerning the laws of the Sabbath, the closed portion of a wall must exceed its open portion, so, too, concerning two of the walls of the sukkah. The leniency allowing a wall of the sukkah to be counted as a wall even though the open portion exceeds the closed portion applies only concerning the third wall. Just as other leniencies (see Halachot 2 and 3) are granted concerning the third wall, this leniency is also allowed.

Others explain that the intent is that even when the open portion of all four walls exceeds the closed portion, the sukkah is kosher, while on the Sabbath such an enclosure is not acceptable. This interpretation of the Talmud's statements is advanced by Rabbenu Asher and is quoted as halachah by the Shulchan Aruch, Orach Chayim 630:5.

If there is an opening larger than ten cubits, it is necessary that the closed portion exceed the open portion even though [the opening] is constructed in the form of an entrance. - Hilchot Shabbat (ibid.) states:

If the open portion is constructed in the form of an entrance, even if it is more than ten cubits long it does not negate the wall, provided the open portion does not exceed the closed portion.

However, the Shulchan Aruch (Orach Chayim 362:10, 630:5) follows the opinion of Tosafot and other authorities, who are willing to accept a wall as kosher even though it has a wide opening, provided it is constructed in the form of an entrance.

The Sefer Hashlamah presents a third view, accepting an open portion more than ten cubits long in the form of an entrance as part of the wall of a sukkah, but not concerning the laws of the Sabbath.

The Ramah concludes his discussion of this halachah by stating that since these laws are somewhat complicated, it has become customary to build whole walls without any open portions. If one has only a minimum amount of wood, it is preferable to build three complete walls, rather than to construct four walls leaving open spaces.

A sukkah whose inner space - the space between the ground and the s'chach.

exceeds twenty cubits [is not acceptable]. - as stated in Halachah 1. Indeed, the question may be raised: Why did the Rambam state these two halachot so far removed from each other?

Should one reduce it - the sukkah's inner space

[by placing] pillows and coverings on the floor], it is not considered to be reduced - for these are merely temporary additions that will later be removed.

[This applies even if] one considered them a permanent - The Maggid Mishneh interprets "permanent" literally. However, the Mishnah Berurah 633:11 explains that according to one opinion, the definition of "permanence" is for the duration of the Sukkot holiday. (See also Ramah, Shulchan Aruch, Orach Chayim 358:2.)

part of the sukkah. - Most people would not consider leaving these articles in the sukkah permanently. Accordingly, a particular individual's desire to do so is not taken into consideration, and the space is not considered to be reduced (Sukkah 4a).

If one reduced the space using straw and considered it to be a permanent part of the sukkah, [the space] is considered to be reduced. - However, if one laid straw on the floor of the sukkah without having such an intention, the space is not considered to be reduced (ibid.). In his commentary on Ohalot 15:6, the Rambam writes: "In general, one will have in mind to remove straw."

The Mishnah Berurah 633:13 emphasizes that one should not reduce the space of the sukkah on the first day of the festival because of the holiday prohibitions. (See also Rabbenu Manoach.)

Needless to say, the above applies if one used earth and considered it to be a permanent part of the sukkah. However, if one [merely brought in] earth with no specific intention, [its space] is not considered to be reduced. - The Shulchan Aruch (Orach Chayim 633:4) quotes these decisions as halachah and adds that one must verbally express the desire to make the earth or straw part of the sukkah. The Mishnah Berurah (ibid.) states that many later authorities considered an unspoken intention as sufficient.

If it - the inner space of a sukkah

was twenty cubits high - and, therefore, unacceptable

but branches [from the s'chach descend within the twenty cubits, [the following principle applies:] If its shade would be greater than its open portion - this is the minimum measure required by the Mishnah (Sukkah 1:1) for s'chach to be kosher.

because of these branches alone - i.e., were the upper portion of the s'chach to be removed, the branches which hang down would create sufficient shade

it is considered as having thick s'chach - i.e., the s'chach is considered to begin at the low branches and to have been piled high.

and is kosher. - The Shulchan Aruch (Orach Chayim 663:2) quotes this law as halachah.

When [a sukkah is more than twenty cubits high, but] one builds a bench next to the middle wall extending across its entire span - and there are fewer than twenty cubits between the bench and the s'chach

if the width of the bench is equal to the minimum width of a sukkah - seven handbreadths, as in Halachah 1 above. See Diagram A.

it is kosher. - Rashi (Sukkah 4a) maintains that not only the area above the bench, but the entire sukkah is kosher, as evident from the last clause of Halachah 3. Though Rabbenu Nissim and other authorities maintain that only the area above the bench may be used as a sukkah, the Shulchan Aruch (Orach Chayim 633:5) accepts Rashi's view.

Should one build the bench next to the middle wall along [one] side, if there are four cubits between the bench and the [opposite] wall, it is unacceptable - because the area around the bench is surrounded by only two walls.

If there are fewer than four cubits, it is kosher. - because of the principle explained in the latter clause. In this instance as well, there is a disagreement between the Rabbis whether the entire sukkah is kosher or only the area above the bench. The Shulchan Aruch (Orach Chayim 633:6) follows the view that only the area above the bench is acceptable for use as a sukkah. See Diagram B.

Should one build the bench in the middle [of the sukkah], if there are more than four cubits from the edge of the bench to any of the sides [of the sukkah] - that wall is too far removed from the bench to be considered to be a wall around it. Hence,

it - the sukkah in its totality, even the area above the bench...

is not acceptable - for in this instance, the sukkah must have four walls.

If there are fewer than four cubits, - between the bench and the walls of the sukkah...

it is kosher. It is considered as if the walls touch the bench i.e., the area from the bench to the wall is considered to be an extension of the wall. Thus, this halachah is the converse of the principle of דופן עקומה (Dofen Akumah - literally, a crooked wall) mentioned in Chapter 5, Halachah 14.

There and in his commentary on the Mishnah (Sukkah 1:10), the Rambam explains that the principle of Dofen Akumah allows us to consider materials on the roof of the sukkah which are unacceptable as s'chach to be extensions of the wall, thus creating an L-shaped - i.e., "crooked" - wall.

Here, the Rambam explains that the opposite is also true. As long as there are no more than four cubits between the bench and the wall, the ground of the sukkah can also be considered to be an extension of its wall. (See Kessef Mishneh.)

and - Since...

the distance from the bench to the s'chach is less than twenty cubits. - as required in Halachah 1, the area above the bench is considered as having four walls and kosher s'chach.

If one constructs a pillar - ten handbreadths or more high, because otherwise, the pillar could never be considered to be a significant domain (Maggid Mishneh).

[within a sukkah - removed four cubits or more from the walls. (Otherwise, it would be considered to be kosher because of the principles mentioned above.)

whose s'chach is more than twenty cubits high, the following rule applies]: Even though it is of the minimum size required of a sukkah - seven handbreadths by seven handbreadths

it is unacceptable - Sukkah 4b explains that Abbaye desires to consider such a sukkah to be kosher, based on the principle of גוד אסיק מחיצתא mentioned in Halachah 11 - i.e., the walls of the pillar would be considered as extending upward until the s'chach. Ravva answered him that, in this instance, that principle cannot be applied...

for - in contrast to those of a house

its - the pillar's

walls are not discernible. - See the Chiddushim of Rav Chayim Soloveichik, Halachah 11.

Thus, it is as if there is kosher s'chach above the pillar without any walls.

[The following rule applies] when [the inner space of the sukkah] was less than ten [handbreadths high] - the minimum height required by Halachah 1.

and one dug [into the ground of the sukkah] to create - a pit at least seven handbreadths by seven handbreadths (Rabbenu Manoach, Shulchan Aruch, Orach Chayim 633:10) with...

an [inner space] of ten [handbreadths] - between it and the s'chach.

If there are three handbreadths from the edge of the pit until the wall [of the sukkah], it is not acceptable. - One might assume that as long as there are less than four cubits between the edge of the pit and the sukkah, the sukkah would be kosher, because of the principle mentioned in the previous halachah; i.e., the ground of the sukkah would be considered to be an extension of the wall. Nevertheless, Sukkah 4a differentiates between the two cases. In the situation described in the previous halachah, the wall was of the proper size; the only question was its proximity to the sukkah. In this instance, there is no halachically acceptable wall to begin with.

If there is less than that [amount], it is kosher - The Mishnah Berurah 633:29 quotes authorities who maintain that only the area within the pit is kosher, and one does not fulfill the mitzvah of eating or sleeping in the sukkah by performing these activities in the portion covered by the s'chach outside the pit.

because any [distance] less than three [handbreadths] is considered to be [insignificant and the two entities are considered to be] adjacent [to each other], as explained in Hilchot Shabbat - 14:7, which explains the principle of l'vud mentioned above.

The walls of the sukkah are kosher [although made] from all [substances]. - The Mishnah (Sukkah 12b) mentions many substances which are not acceptable as s'chach (as mentioned in the following chapter), and concludes "all are fit to be used as walls."

All that is necessary is a barrier of any kind. - The Ramah (Orach Chayim 630:1) explains that one should take care not to use substances that have an unpleasant odor or substances that will shrivel during the holiday, and thus cause the walls to be less than the required measure.

Even living beings [may serve that purpose. - The Shulchan Aruch (Orach Chayim 630:11) states that an animal used for this purpose must be tied so that it will not run away.

Thus,] a person can create a wall [of the sukkah] by using a colleague so that he can eat, drink, and sleep in the sukkah, for which his colleague is serving as a wall - The Tzafnat Paneach raises the question whether the person serving as the wall can also fulfill the mitzvah of eating in such a sukkah. He quotes a number of passages from which one might infer that he may.

[even] on the holiday. - The latter term refers to the first day of Sukkot - and in the Diaspora, the second day - and the day of Shemini Atzeret, when the laws prohibiting work and the Rabbinic ordinances extending those restrictions must be observed.

The above applies when one employs the person as a wall without his conscious knowledge. However, it is forbidden to create [a wall by using a person] - The Ra'avad and the Maggid Mishneh explain that this refers only to the third wall of the sukkah. If a sukkah has three kosher walls, a person may employ a colleague to serve as the fourth wall on the holiday, even though the latter is conscious of what he is doing. The Ramah (Orach Chayim 630:12) states this as halachah.

when the latter is conscious of the fact on the holiday. - Hilchot Shabbat 16:23 states:

It is permitted to create a barrier of men, one standing next to the other, on the Sabbath, as long as the people who are standing are not conscious of the fact that they are serving as a barrier.

Although it is forbidden to create an enclosure on the Sabbath, since the person serving as the barrier is unaware of what he is doing, no transgression is involved. It is his intention, and not that of the person using the sukkah, which is significant (Ra'avad). In contrast, when the person serving as the wall is conscious of his acts, it is considered as if he has created a structure of substance (Magen Avraham 630:19).

The Magen Avraham (ibid.) also states that leniency is granted only when humans serve as the walls. It is absolutely forbidden to create a wall using an animal on the holiday.

Nevertheless, it is permitted during the other days of the festival - with the exception of the Sabbath; i.e., there is no essential difficulty with the use of such a sukkah, the only problem is the Rabbinic prohibition mentioned above.

Similarly, a person may create a fourth wall - Since a sukkah is kosher when it possesses only three walls, the addition of the fourth wall is not halachically significant. We are allowed to add to a temporary structure on the Sabbath.

from utensils on the festival. However, he should not create a third wall using utensils - It is permitted to create a utensil from human beings, because one does not normally create an enclosure in such a manner. In contrast, an enclosure is frequently made from utensils (Rabbenu Manoach).

on the holiday, because, [by doing so], he is making the sukkah fit for use, and it is forbidden to create [even] a temporary tent on the holiday.