Rambam - 3 Chapters a Day

Sefer HaMitzvot (positive commandment 81) and Sefer HaChinuch (mitzvah 22) include this commandment among the 613 mitzvot of the Torah.

In contrast to the mitzvah of redeeming one’s firstborn son, this obligation is incumbent on both males and females.

If, however, the first issue of the donkey is female, it need not be redeemed.

The Hebrew term seh can refer either to a sheep or a goat, as stated in Halachah 8.

Sefer HaMitzvot (positive commandment 82) and Sefer HaChinuch (mitzvah 23) include this commandment among the 613 mitzvot of the Torah. The Ra’avad objects to this being considered as a separate mitzvah. In Sefer HaMitzvot, loc. cit., the Rambam explains that he considers the two as separate mitzvot, because Bechorot 13a refers to them as such and draws a parallel between these mitzvot and the mitzvot of yibbum and chalitzah which are accepted as separate mitzvot. Bechorot 10b explains the rationale for this mitzvah, since the owner caused a priest a loss (by not redeeming the firstling donkey), the Torah decreed that he suffer financial loss. In his Moreh Nevuchim, loc. cit., the Rambam explains that this mitzvah is a safeguard to insure that the mitzvah to redeem the firstling donkeys is observed.

The Hebrew term seh can refer either to a sheep or a goat, as stated in Halachah 8.

I.e., its observance is not limited to Eretz Yisrael, nor to the time when the Temple is standing.

I.e., the initial preference is to redeem the animal rather than behead it.

The verse establishes an association between the redemption of a firstborn son and the redemption of a firstling donkey. Just as the money for the firstborn is given the priest, so to, the seh for the firstling donkey is given him (Radbaz). Nevertheless, as evident from Halachot 5-6, the association is not complete in all of its particulars.

The Rambam clarifies this because from a simple reading of the verse, one might infer that all the firstborn of impure animals must be redeemed. Although all firstborn humans must be redeemed and all firstborn kosher animals must be sacrificed and/or given to a priest, among non-kosher animals, it is only among donkeys that the firstborn is designated as unique and requiring redemption. In his Moreh Nevuchim, Vol. III, ch. 39, the Rambam explains that this mitzvah is also connected with the commemoration of the exodus when God slew the Egyptian firstborn. It is associated with donkeys and not other beasts, because donkeys are a necessity in an agricultural society. Rashi (Exodus 13:13) focused on different dimensions of this concept, stating that a) donkeys are used as an
analogy for the Egyptians, and b) the donkeys assisted the Jews in their redemption, for they carried the wealth of Egypt upon them.

The Ra’avad questions the Rambam’s ruling, asking: “Why can he not give the money he received for the donkey to the priest? Why is it forbidden?” After all, it is permitted to redeem the donkey for its value (Halachah 11). The Radbaz explains that initially, if the person would desire to pay the donkey’s worth to the priest, he could have done so. Here, however, he sold the donkey and once it was sold, the money he received is forbidden. Shulchan Aruch (Yoreh De’ah 321:8) quotes the Rambam’s ruling. The Rama states that if the seller notifies the buyer that it is the first issue of a donkey, stipulates that the buyer will redeem it with a seh, and states that he is selling him the difference between the value of the seh and the value of the donkey, the sale is permitted

I.e., the priest sets aside a seh and redeems the donkey with it. He then takes the seh as his own.

For they say: "Why should I redeem it when I am entitled to keep the seh with which I redeem it?" (Siftei Cohen 321:6).

As soon as the seh was set aside, the holiness of the donkey is transferred to it. Hence, when the seh dies, it is considered that the priest’s property died and the owner is not under any further obligation (Rashi, Bechorot 9a).

For the seh already became the priest’s property [the Rambam’s Commentary to the Mishnah (Bechorot 1 :4)].

Again since the redemption is already a fait accompli, the priest deserves the seh regardless of what happens to the donkey.

The Shulchan Aruch (Yoreh De’ah 321:1) states that the mitzvah is “to redeem it
immediately, so as not to postpone the observance of the mitzvah.”

In this, we see a difference between the redemption of a firstling donkey and that of a firstborn son. For the son must be redeemed after 30 days, not before (Chapter 11, Halachah 17).

Our translation is taken from the Rambam’s Commentary to the Mishnah (Bechorot 1:7).

This is implied by the Hebrew term erafto that is connected to the Hebrew oref, meaning “neck.” One must decapitate the animal, severing its neck (ibid.).

The Turei Zahav 321:3 notes that, as stated in Halachah 11, one may redeem the firstling donkey for its value. Hence, if one tells a priest that by giving him a calf or the like, he is redeeming the donkey for its value, the redemption is effective.

See Chapter 9, Halachah 5, and notes, with regard to the definition of this term.

For even if it does not appear to be a seh, it is of that species. Bechorot 12a raises this
question and does not resolve it. Hence, as an initial preference, one should not use such an animal, but after the fact, it is acceptable (Radbaz, Kessef Mishneh). The Rambam’s opinion is quoted by the Shulchan Aruch (Yoreh De’ah 321:3), but the Tur and the Rama differ and maintain that the status of such a redemption is questionable.

This term refers to an animal that was being carried as a fetus when its mother was slaughtered and remained alive despite that slaughter (see Hilchot Ma’achalot Assurot 5:14). The Rambam’s opinion is quoted by the Shulchan Aruch (Yoreh De’ah 321:4), but the Tur and the Rama differ and maintain that the redemption is invalid.

As stated in the previous halachah.

See Hilchot Shemitah VeYovel, ch. 6, which explains the laws governing the use of money received for the sale of the produce of the Sabbatical year in detail.

The sheep purchased with money from the sale of produce of the Sabbatical year is considered as the produce of the Sabbatical year itself. And the produce of the Sabbatical year should not be used for the purchase of a non-kosher animal (Hilchot Shemitah VeYoval 6:10).

As stated in Halachah 21, when redeeming a donkey whose firstling status is questionable, it is necessary to separate a sheep, but one does not have to give it to the priest. Hence, using a sheep for this process is not considered analogous to the purchase of a non-kosher animal with the produce of the Sabbatical year.

See the Minchat Chinuch (mitzvah 22) who concludes that when the owner does possess a seh, he must redeem the donkey with the seh rather than pay its value.

See the Or Sameach and the Minchat Chinuch (loc. cit.) who question whether, after the fact, the redemption of a firstling donkey is effective if one gave less than its worth. One might argue that the priest receiving the article could say: “For me, this is worth the value of the donkey.” Indeed, Hilchot Arachin 7:8 states that when one redeems consecrated property for less than its value, the redemption is valid. This position, however, is not accepted by all authorities. Compare to Chapter 11, Halachah 7.

And require that a sheep be given, regardless of the difficulty involved.

A dinar is equivalent to one fourth of a sela.

That a firstling donkey should be redeemed for its value or for a seh.

A zuz is equivalent to a dinar.

The Rambam’s ruling is based on his interpretation of Bechorot 11a. Rashi and the Ra’avad offer a different interpretation of that passage. In his Kessef Mishneh, Rav Yosef Caro questions the Rambam’s ruling, stating that the Ra’avad’s interpretation appears closer to the version of the Talmud we possess. Nevertheless, in his Shulchan Aruch (Yoreh De’ah 321:5), Rav Yosef Caro quotes the Rambam’s view.

Note the Minchat Chinuch (loc. cit.) who questions whether the mitzvah is incumbent on the owner of the donkey and the person is thus acting as the owner’s agent or whether the mitzvah to redeem it is incumbent on the Jewish people as a whole and any person has the right to observe it. There would be a practical difference between these two views if the owner protested against the other person redeeming his firstling donkey.

The Rama (Yoreh De‘ah 321:19) states that this also applies to women of the priestly and Levitical families. Nevertheless, this applies only to the donkeys that they personally own. Those owned by their husbands are liable.

And the priests and Levites are exempt from the redemption of their firstborn, as stated in Chapter 11, Halachah 9

This refers to the second clause. He is forbidden to sell his firstling donkey as a fetus to a gentile, for by doing so, he exempts himself from the mitzvah of redeeming it and thus causes the priesthood a loss. There is, however, no prohibition against purchasing a firstling fetus owned by a gentile {Radbaz).

In general, it is forbidden to enter into a partnership with a gentile (Hilchot Shiluchim VeShutafim 10:5). In particular, this applies in the present instance, for he is depriving the priesthood of the presents due them. Nevertheless, he is not penalized for doing so.

For, as the Rambam concludes, the firstling donkey must belong entirely to a Jew. a

The Tur and the Shulchan Aruch (Yoreh De’ah 321:20) state that, in this regard, the laws that apply to a firstling donkey are the same as those applying to the firstborn of a kosher animal and they are discussed in sec. 320 which deals with that subject.
There the Tur asks why is it necessary for the Rambam to speak of the limbs of an animal when he already mentioned that any small percentage of a partnership in the animal disqualifies it. The Kessef Mishneh explains that in this clause, the Rambam is speaking about an instance where the gentile is not a partner in the entire animal. He owns only a portion of the particular limb or organ in question. Hence, it is necessary to clarify that even in such an instance, he is exempt.

I.e., if such a blemish were to exist in a kosher animal. These blemishes are mentioned in Hilchot Issurei Mizbeach, ch. 2.

This was a common practice in the Talmudic era. A person would give a colleague a donkey (or other animal) to raise. As payment for raising it, he is given a half share in the donkey’s offspring. See the Rambam’s Commentary to the Mishnah (Bechorot 1:1).

In which case he would be exempt from redeeming its firstborn.

In which case he would be obligated.

When quoting this law, the Shulchan Aruch (Yoreh De’ah 321:18) does not mention the option of decapitation, implying that even in this instance, redemption is the preferable option.

This instance is different from that involving the presents of meat given to the priests (Chapter 9, Halachah 13). The rationale is that in this instance, the owner is forbidden to benefit from the firstling donkey unless he redeems it. Hence, he must redeem it rather than risk that transgression. Moreover, as the Rambam proceeds to explain, he does not suffer any loss through this redemption.

A priest who is claiming that he is entitled to the seh for the redemption would have to prove that the conversion took place before the donkey was born. The owner is allowed to keep the seh, for there is no holiness associated with it. The question is only one of monetary law and is governed by the principle stated by the Rambam.

We inform him, lest he think that the Jews are lax in the observance of sanctified articles (Siftei Cohen 321:13).

For the mitzvah only applies to the Jewish people.

Exodus 13:13, 34:20.

The Shulchan Aruch (Yoreh De‘ah 315:6) is more lenient, stating that there is a doubt whether it must be redeemed.

Even though he does not know which one is the firstborn, one of them obviously is. Hence, an obligation exists.

A priest who is claiming that he is entitled to the seh for the redemption would have to prove that the male donkey was born first.

For it is only certain that one of the males was the firstborn. The female could have been born before the second one. See Chapter 11, Halachah 22. Although there is a possibility that the second donkey gave birth to a male first, there is no probability that it did so. Hence the Rambam does not require that a lamb be separated for it. The Tur and the Shulchan Aruch (Yoreh De’ah 321:14) maintain that since there is a possibility that the second male is also a firstborn, the owner should separate a lamb to remove the possibility of any holiness being attached to the donkey, but he may keep the lamb as his own.

Because there is no probability that the donkeys gave birth to a male first. In each instance, it is possible that the donkey gave birth to a female before the male.

The Ra’avad and other commentaries question the Rambam’s logic and ruling,
because this is not the usual instance of a sefek-sefeka. When the situation is analyzed, the only real question is: Was the male born after a female or not? Hence since there is a doubt, it would seem appropriate for a lamb to be separated (and kept by the owner) to remove the possibility of the donkey being holy. The Shulchan Aruch (Yoreh De‘ah 321:14) follows the Rambam’s view, while the Tur and the Rama require that a lamb be set aside. As Siftei Cohen 321 : 11 writes, since the owner will not suffer a loss by separating a lamb, why shouldn’t he?

For one of the males is definitely a firstborn.

For perhaps the donkey that gave birth previously gave birth to the male.

The fact that originally, there was a claim against them is not significant. Since the owner is allowed to maintain possession, as stated in the above halachot, there is no difference between these lambs and the remainder of his property.

See Hilchot Bechorot, ch. 6, which describes this mitzvah. Since these lambs are ordinary property and are not consecrated, they must be tithed.

For since, they originally belonged to an Israelite, there is an obligation to redeem them.

His grandfather, the priest would not have to give the lambs he set aside to redeem them to another priest, because he himself is entitled to them. He bequeaths that right to his grandson, the Israelite. Hence he may keep them as his own.

For they are not consecrated.

Sefer HaMitzvot (positive commandment 135) and Sefer HaChinuch (mitzvah 112) include this commandment among the 613 mitzvot of the Torah. There is a difference of opinion among the commentaries if the mitzvah is incumbent on the gavra (the person himself) or on the land (the cheftza, the object). The commentaries note that the Rambam’s wording in this halachah indicates that the mitzvah is on the person, that he should rest and not perform work. Nevertheless, the wording he uses when enumerating the mitzvot - that “the land should rest” - puts the emphasis on the land.

The citation of this verse reflects a general principle in the Mishneh Torah: that the Rambam will occasionally favor the understanding of a verse proposed by the Jerusalem Talmud even though the Babylonian Talmud interprets it otherwise. To explain: the Babylonian Talmud (Mo ‘ed Kattan 4a) interprets this verse as a prohibition to work the land on the Sabbath. It is the Jerusalem Talmud (Sh’vi’it 1 :3) which understands it as referring to the Sabbatical year. From Chapter 4, Halachah 1, it appears that here the Rambam is speaking of harvesting for the sake of improving the land, not for gathering its crops. The intent appears to be that harvesting produce will enable the land to produce better produce in the future.

This mitzvah is incumbent both on men and women.

Sefer HaMitzvot (negative commandment 220) and Sefer HaChinuch (mitzvah 326) include this commandment among the 613 mitzvot of the Torah.

As indicated by Halachah 20 and notes, the intent here is trimming the top of the tree and not the end of its branches.

The term betzirah whose root is used in Leviticus 25:5 is usually employed specifically with regard to harvesting grapes. Nevertheless, in a wider sense, it refers to harvesting any fruit.

Because like sowing, trimming contributes to the growth of the tree (Radbaz).

In Leviticus 25:5: “The aftergrowth of your harvest you shall not reap and the grapes you had designated you shall not gather.”

And performing work with trees.

Plowing is explicitly mentioned in the positive commandment for observing the Sabbatical year, but not in the prohibition. Although Mo ‘ed Kattan 3a uses techniques of Biblical exegesis to show that other labors are forbidden, the Rambam considers these teachings merely as asmachteot, citing a verse as support for a concept forbidden by Rabbinic Law.

To improve the land, not because he needs the stones. See Chapter 2, Halachah 10.

In his Commentary to the Mishnah (Sh’vi’it 2:2), the Rambam writes that this is beneficial for certain trees.

As will be explained (see Halachah 7), we are permitted to perform labor to maintain a tree’s wellbeing. These activities, however, are intended to foster its growth.

Both of these activities speed their ripening (Sh'vi'it 2:5).

For this prepares the land on which they grow to be used to plant crops.

And not on land that could be used for crops in which instance, the plowing would a benefit him.

For this resembles sowing them.

Because we do not usually sow in dung.

For this does not involve working with the land.

For that would promote their growth, not merely maintain them.

The Kessef Mishneh quotes Rashi (Mo ‘ed Kattan 3a) who explains that the words oder and kishkush are synonymous. The difference is only with regard to the type of plants.

For otherwise all the trees in the field will die, as stated in Halachah 10.

For that is the most effective way of watering the trees, since they are close to each other.

Since it is unnecessary to do that to provide the individual trees with water.

Our translation is based on the Rambam’s Commentary to the Mishnah (Mo ‘ed Kattan I: 1).

Our translation is based on the Rambam’s Commentary to the Mishnah (Kelayim 5:4).

So the trees will not die.

In Halachot 2-3.

Our translation is based on the authoritative manuscripts and early printings of the Mishneh Torah. The standard published text follows a slightly different version.

This leniency was granted even though sowing is forbidden by Scriptural Law. It must, however, be emphasized that (as stated in Chapter 10, Halachah 9), from the later years of the First Temple period, the observance of the Sabbatical year only had the status of Rabbinic commandment. The Radbaz maintains that such leniency would be granted even if the Scriptural ordinance was in effect.

For since he is being threatened, it makes no difference whether the person threatening him is a king or an ordinary person. Since there is danger involved, leniency is granted (Radbaz, Kessef Mishneh). The Kessef Mishneh emphasizes that this leniency is granted only when the person does not receive payment for his activity. He is forbidden to take payment, even if he is being compelled, for then a person could perform such labors and excuse himself, claiming that he was compelled to do so.

Terumot 2:3 contrasts sowing on the Sabbath with sowing during the Sabbatical year, explaining that the Jews are not suspect to violate the Sabbath. Hence, the results of the inadvertent violation of the Sabbath laws are not forbidden.

This is the translation of the word nirah, based on the Rambam’s Commentary to the Mishnah (Sh’vi’it 4:3, Pe’ah 2:1). The term differs from plowing in that it is a far less thorough activity. See Rashi’s gloss to Jeremiah 4:3 which explains that it refers primarily to the removal of weeds, thorns, and the like.

In his Commentary to the Mishnah (Sh’vi’it 4:2), the Rambam explains that this applies even if the field is fertilized by making it a corral for animals, so that their manure will fertilize it and improve its quality

For the penalty is imposed on him personally, not on the land. Note the contrast to Chapter 3, Halachah 11.

As stated in Halachot 4 and 16.

In these eras, there was no refrigeration and vegetables would be preserved by placing them in the ground.

As long as the leaves are revealed, one is not planting in the ordinary manner (Radbaz). Burying the plants in this manner is permitted, because he does not desire that the plants grow in the earth; they are merely buried there [the Rambam’s Commentary to the Mishnah (Kilayim 1 :9)].

Because he appears to be planting them.

If they are not packed so densely, burying them resembles planting [ibid. (Sh’vi’it 5:2)].

Our translation is based on Rav Kappach’s notes to the Rambam’s Commentary to the Mishnah (ibid. 2:10). There the Rambam explains the term yichsech, but does not explain the term mere is. The Radbaz and the Kessef Mishneh interpret the latter term as meaning that it is permitted to sprinkle water on the rice plants. The contrast to the following clause supports Rav Kappach’s interpretation.

Those that stick out and attract attention [the Rambam’s Commentary to the Mishnah (Pe’ah 6:11; Sh’vi’it 4: l)].

I.e., when clearing the land, one takes smaller stones and pieces as well as larger ones, so that the land will not have any foreign matter upon it.

It would appear that a person would be permitted to gather both larger and small pieces from his colleague’s field. The Radbaz, however, grants this leniency only with regard to larger pieces.

Our translation is based on the Rambam’s Commentary to the Mishnah (Sh’vi’it 4: I). There he emphasizes that the person clearing the field is expecting something in return.

Not only the large ones permitted in the previous halachah. Even though the person’s field will be cleared in this manner, since this is not his intent, and the labor of clearing a field involves merely a Rabbinic prohibition, stringency was not enforced.

That he is seeking to provide his animal with food and not clear his field.

The Radbaz states that this leniency is granted only when the owner takes both the large and small pieces. If he takes only small pieces, it is forbidden because he is obviously intending to clear his field.

Even though it involves work with the land, since he desires the wood, it is permitted.

The place where three trees can grow is significant and can be used for planting. Thus by removing. the stumps, it is as if he is clearing a field for himself [the Rambam’s Commentary to the Mishnah (Sh’vi’it 5:4)].

The intent is not that one has uninhibited license to cut down a colleague’s tree even in the Sabbatical year. Instead, if the tree has been cut down, one may uproot the stump.

See Chapter 5, Halachot I 7-18, which restricts cutting down trees for kindling once they have begun to bear fruit.

This is forbidden by Scriptural Law.

In his Commentary to the Mishnah (Sh’vi’it 4:7), the Rambam explains that there is no need for a deviation in the way he trims the branches, because he is not intending to trim the tree. To explain his statements: Although trimming is one of the activities forbidden by Scriptural Law, this refers to trimming the top of the tree, not the ends of its branches (Tifferet Yisrael to the above mishnah).

Our translation is taken from the Rambam’s Commentary to the Mishnah (Sh’vi’it 5:5)].

Here, also, our translation is taken from the Rambam’s Commentary to the Mishnah (Sh’vi’it 5:5)], which quotes I Samuel 15:33 as support.

As mentioned in Chapter 1, Halachah 4, fertilizing is a task forbidden by Rabbinic Law.

Because it does not appear that he is preparing to fertilize his field immediately.

Our translation is taken from the Rambam’s Commentary to the Mishnah (Sh’vi’it 3:1)]. There he explains that although matok, the name the Mishnah uses, means “sweet,” this fruit has a bitter taste and that term is used as a euphemism. Some have identified this species with the colocynth, a wild gourd with a very bitter flavor. The Radbaz identifies it with a bitter species of grass.

Anything smaller might convey the impression that he is fertilizing his field. a

Hilchot Shabbat 16:3 defines an area in which a se’ah of grain is sown as 50 cubits by 50 cubits. In this instance as well, if he makes more than three waste heaps, it might appear that his intent is to fertilize the field.

I.e., we are not concerned that an onlooker might think that he is fertilizing his field.

I.e., create one very large waste heap that encompasses a greater area than the three waste heaps in a 2500 sq. cubit area.

By fertilizing it, for the waste is not in direct contact with the earth.

For use after the Sabbatical year.

I.e., according to the guidelines established in the previous halachot.

The Ra’avad cites the Jerusalem Talmud (Sh’vi’it 3:4) which emphasizes that the person’s intent should not be to fertilize his field, but to take care of his sheep. When he does that, he can have a portion of his field fertilized as a by-product.

100 by 50 cubits.

I.e., when an observer will see that the entire field was not fertilized, he will realize that the person did not fertilize it by hand, because then there would be no purpose in leaving part of it unfertilized.

The Radbaz explains that the Rambam’s ruling applies whether the quarry is open or underground. There are, he explains, other opinions that maintain that if the quarry is open, there is no obligation to begin extracting the stones before the Sabbatical year.

Provided one’s intent is genuinely to quarry stone and not to improve the field (Radbaz).

I.e., all the stones, even those smaller than the size specified.

When a person is taking many stones of this size, the effort involved clearly indicates that he is intending to use them for building and not merely to improve his field.

So that he will not have prepared his field by removing the stones.

That he must leave a row of stones a handbreadth high above the earth.

By leaving an additional area that he could sow in the following year.

The Radbaz asks: We see that our Sages forbade certain activities because of the impression that an observer might derive. If so, what does the owner’s intent matter? An observer may think that he is intending to clear his field. For this reason, he explains that the owner must perform an activity that makes it obvious that he is intending to use the stones for building, for example, using them for construction that is presently being performed on his property.

This indicates that he was not using the Sabbatical year to perform whatever work that was possible in his field.

I.e., even small stones and even when he tears down a wall that is less than ten handbreadths high.

I.e., a person who hires out the field for his own purposes. See Halachah 12 and the Rambam’s commentary to its source (Sh’vi’it 3:9).

Because he would not take the stones unless they would benefit him. Needless to say, one may not destroy a wall in a colleague’s field at whim. Thus even when the owner knows that the wall is being torn down, as long as it is being torn down to be used for building, it is permitted to do so.

For, as above, the size of these stones indicates that they will be used for building. The implication is that not only is the person allowed to remove these two large stones, he is allowed to remove all the stones in the field (Radbaz). Needless to say, this leniency is granted only when he genuinely intends to use the stones for construction, not when he desires to clear his field.
One might ask: Why are only two stones required to be of this size in this instance, while in Halachah 8, ten large stones are required? Among the answers given is that in this instance, since the stones are scattered over a larger area, their removal is less likely to be noticed by an observer. In Halachah 8, by contrast, since the stones are all located in one place, an observer will see that they have been removed (Pe ‘at HaShulchan).

Lest an observer think that he is intending to clear his field.

For if he desired to clear his field, he would take the large stone or straw that is beneath them as well.

And such work is forbidden in the Sabbatical year.

Our translation and the bracketed addition are based on the Rambam’s Commentary to the Mishnah (Sh’vi’it 3 :8).

If, however, he must descend into the groove to pick up a stone, it is forbidden to remove it, lest an impression be created that the person is seeking to improve his field and make the groove fit for sowing (ibid.). The Ra’avad objects to the Rambam’s ruling, offering a different interpretation of his source (Sh’vi’it, loc. cit.). [The Ra’avad’s interpretation is paralleled by Rabbenu Shimshon’s understanding of that mishnah.] The Radbaz and the Kessef Mishneh offer different explanations that reinforce the Rambam’s understanding.

A person who had hired the field. See Halachah 8.

Even though he hired the field, it is not his own and we do not suspect that he will transgress to improve it. The Ra’avad understands Sh’vi’it 3:9, the Rambam’s source differently, seeing it as interrelated to the concepts mentioned in the previous halachah.

I.e., rather than being rebuilt with stone.

For an onlooker will think that the person is rebuilding it for the purpose of improving his field and enabling him to sow it the. following year. See the explanations in the notes to the following halachah.

For an observer will understand that he is rebuilding it to remove an obstacle for people at large. (Alternatively, when there are obstacles for people at large, we do not enforce restrictions instituted only because of the possibility that an observer will derive a mistaken impression.)

In this situation, by closing it, he is creating a divider between his field and the public domain.

The Ra’avad differs with the Rambam’s ruling, maintaining that since there is a gap in the fence separating his field from the public domain, he is allowed to rebuild it in all instances. The Ra’avad and the Kessef Mishneh note that the Jerusalem Talmud (the conclusion of ch. 3 of Sh’vi’it) supports the Rambam’s position.

Building a wall between one’s own field and a colleague’s is prohibited lest an onlooker think that one is preparing the land in order to sow one’s field. Alternatively, we fear that the person may change his mind and sow the land (Radbaz). A person is, however, permitted to build a wall between his own field and the public domain to set off his property from the public domain. Alternatively, it is not common to sow the land next to the public domain, so there is no need for the above suspicions.
In the previous halachah, repairing a wall between one’s field and the public domain is prohibited when the open space is filled with earth. Here, since it is entirely open, a wall may be built, as in the latter clause of that halachah.

Since he digs until a stone, but does not remove the stone, it is clear that his intent is not to improve his field, for one cannot sow on a stone.

But not in the public domain. See Sh’vi’it 3:10.

See Halachot 1-3.