Rambam - 1 Chapter a Day

Whose halachic obligations are equivalent (Chagigah 4a).

There are opinions that state that a woman does not have to recite the part of grace that blesses God for “Your covenant that You have sealed in our flesh, and for Your Torah that You have taught us,” since women are not obligated to fulfill these mitzvot. Nevertheless, in practice, it is agreed that women should mention both these mitzvot, because the ultimate fulfillment of the creation of both men and women is when they marry. Therefore, a man and his wife are considered a single unit (Shulchan Aruch HaRav 187:7).

Women are not obligated to fulfill such mitzvot. See Kiddushin (1:7). Since the obligation to recite grace is constant, whether one eats during the day or at night, it would appear that women are obligated. Some commentaries point to Sefer HaMitzvot (positive commandment 19) and the Rambam’s Commentary to the Mishnah (Berachot 3:3 and Kiddushin, loc. cit.) as indications that the Rambam supports the view that a woman’s obligation for grace stems from Scriptural Law.

Berachot 20b explains this hypothesis: Since Deuteronomy 8:10, the proof-text requiring us to recite grace, states: “You shall bless God, your Lord, for the good land that He gave you,” one might think that only those who were given an inheritance in Eretz Yisrael are required to recite grace, thus excluding women who were not given an inheritance.

I.e., because of this doubt.

Since, as stated in Chapter 1, Halachah 11, a person can only recite a blessing on behalf of another person if he shares an equal obligation himself.

Boys below the age of thirteen and girls below the age of twelve, or individuals above that age who have not demonstrated signs of physical maturity.

This expression appears to indicate that the Sages placed the obligation on the child himself. See also Hilchot Sukkah 6:1 and Hilchot Lulav 7:19, where the Rambam uses similar expressions. (In Hilchot Tefillin 4:13 and Hilchot Chagigah 2:3, however, the Rambam states that the obligation to train a child to fulfill these mitzvot lies on the father.)
The hypothesis that the obligation lies on the child is supported by Halachah 16, which states that a child may fulfill the obligation of grace for a person who did not eat to the point of satisfaction (and, therefore, is obligated to recite grace only by Rabbinic decree). Were the Sages to have placed the obligation to educate the child on his father and not on the child himself, the child would not be able to fulfill the mitzvah on behalf of another person.
Nevertheless, it is possible to explain that the Sages placed the obligation on the father. This obligation, however, encompasses the child and, hence, causes him to be considered as obligated in the mitzvah (Likkutei Sichot, Vol. 17).

Until a child reaches intellectual maturity, Scriptural Law itself places no obligations upon him (Pesachim 116a).

. I.e., if there are two adult males and one of these three types of individuals, it is impossible to make a zimmun. The Shulchan Aruch (Orach Chayim 199:7) states that when women eat together with men who make a zimmun, they are obligated to answer.
. If any two of these three categories of people eat together, there is a possibility of undesirable results. In order not to encourage such meals, the Sages did not permit zimmun.

If any two of these three categories of people eat together, there is a possibility of undesirable results. In order not to encourage such meals, the Sages did not permit zimmun. The Rambam mentions modesty only as a reason why women and servants should not join in a zimmun. Significantly, other authorities explain that it is for reasons of modesty that women should not be counted in a zimmun together with men.

Nor should a company consist of two of these three categories.

There is, however, no obligation for them to do so (Shulchan Aruch, Orach Chayim 199:7). Rabbenu Asher considers them as obligated to make a zimmun. Nevertheless, even among the Ashkenazic community, most authorities do not accept his ruling.

The mention of God’s name causes the recitation of grace to be considered “a holy matter.” As stated in Hilchot Tefillah 8:6, prayers of this nature can be recited only when a quorum of ten adult males is present (Kessef Mishneh).

A person who possesses both male and female sexual organs.

Since he is not a member of either sex.

A person who has flesh covering his genitalia, making it impossible to determine whether he is a male or a female.

He should not be counted among men or women, because we are unsure of his gender. Furthermore, unlike androgynoses, a group of tumtumim cannot make a zimmun of their own.
In the case of an androgynous, the doubt is how to define his halachic status properly. Hence, they are considered a separate category. In contrast, a tumtum is either a male or a female, and it is his physical condition that prevents us from determining his gender. Thus, a group of tumtumim may include both males and females, and hence they are not allowed to be counted in a zimmun at all (Kessef Mishneh).

The Magen Avraham 199:6 states that this applies to only one child, but not two or more.

Rav Yitzchak Alfasi mentions an age of nine or ten. The Beit Yosef (Orach Chayim 199) states that all authorities agree that a child below the age of six may not be counted in a zimmun.

To recite the zimmun together with two adult males.

To include the mention of God’s name together with nine adults.

Rabbenu Asher and the Rama (Orach Chayim 199:10) do not accept this distinction, and rule that a child may not be counted in a zimmun until he is thirteen years of age and has exhibited signs of physical maturity.

Even when we are certain that he will bless God.
In his Commentary to the Mishnah (Berachot 7:1, based on Berachot 47b), the Rambam states that this refers to a gentile who has already made a decision to convert and has been circumcised for that reason. Nevertheless, if he has not immersed himself in the mikveh, he is not considered a Jew, and may not be included in a zimmun.

Most authorities differ with the Rambam concerning this point and allow a person to be included in a zimmun even if he only partook of vegetables or drank a beverage (Shulchan Aruch, Orach Chayim 197:3).

It is possible to explain that this is referring to three individuals who each began eating with a separate group in the same large room. Afterwards, they joined together and ate at the same table.
Alternatively, the halachah is speaking about three groups that ate at the same table, and one remained from each group (Merkevet HaMishneh), or the three individuals came from different groups, but left their original group inadvertently or because of forces beyond their control (Mishnah Berurah 193:31).

And thus were each personally obligated to participate in a zimmun (Rashi, Berachot 50a).

Even when they themselves do not eat together (loc. cit.). According to the Kessef Mishneh, this applies when they eat together. The Shulchan Aruch (Orach Chayim 193:5) states that, in either instance, the following law applies.

Ideally, they should not have separated from their first company. See the Rishon LeTzion; Rama, Orach Chayim 193:6). After the fact, since they all have still not recited grace and are all obligated to participate in a zimmun, they should do so.

I.e., although they desired to continue eating, they responded to the zimmun and listened to the first blessing of grace (Tosafot, Berachot, loc. cit.; Rama, Orach Chayim 200:2)

The Shulchan Aruch (193:5) states, “They cannot...”; i.e., it is forbidden for them to participate in a zimmun again.

Even though one of the three desires to recite grace before the others, they must recite the zimmun as a group (Mishnah Berurah 193:28).

It is the intent to sit down together at a single table that establishes them as a company, and not the fact that they share food.

This halachah describes a large feast, at which many people eat at different tables. Nevertheless, they all came together for the same purpose, and thus are considered a single group. (See the Jerusalem Talmud, Berachot 7:5; and Shulchan Aruch HaRav 195:2).
In contrast, in a restaurant, although many people eat in the same room, since they did not come with the intention of eating together, they are not considered as a single group.

The Rambam is quoting the Mishnah (Berachot 7:5). Rabbenu Asher and the Shulchan Aruch (Orach Chayim 195:1) state that the same principles apply if the feast is held in two separate rooms (or houses), as long as they are not separated by a street.

Similarly, if a single group is large enough to prevent the words of the blessings from being heard, people should recite the zimmun in smaller groups (Kessef Mishneh; Shulchan Aruch, Orach Chayim 193:1).

He must also respond (Berachot 45b; Mishnah Berurah 194:6).

He fulfills his obligation for zimmun, but not for grace.

It is only proper that God’s name be mentioned when the ten people are in the same room (Berachot, loc. cit.).

If, however, two people from a group of three recite grace alone, a zimmun may not be recited (Shulchan Aruch, Orach Chayim 194:1).

The Rama (Orach Chayim 194:1) states that this law only applies when the individual has not answered to a zimmun previously. If, however, he answered to the zimmun of a previous group, he may not be included in this zimmun.

He should respond as usual.

Zimmun should precede grace. Once a person has recited grace, he can no longer fulfill his obligation for zimmun.

And thus a zimmun may not be recited.

The Shulchan Aruch (Orach Chayim 193:1) uses the expression, “It is a mitzvah for them to separate.” At the beginning of a meal (see Chapter 1, Halachah 12), one person may recite the blessing on behalf of another. At the conclusion of the meal, however, it is preferable for each person to recite grace himself, since the two people have concluded eating and are already considered to have parted from each other (Tosafot, Berachot 45b).

So that the other person can hear each word of the grace. The Shulchan Aruch (Orach Chayim 213:3) rules that the person reciting the blessing also must intend that the listener fulfill his obligation by hearing the blessing. (See Chapter 1, Halachah 11, and notes.)

See Chapter 1 (op. cit.), which explains that although one may fulfill his obligation without answering Amen, it is preferable to do so.

See the Shulchan Aruch (Orach Chayim 193:1), which states that the person who fulfills his obligation by listening must also understand the words the person reciting grace is saying. Later authorities (see Shulchan Aruch HaRav 185:1 and the Mishnah Berurah 193:5) state that although it is preferable that they recite grace themselves (even in translation), they may fulfill their obligation by listening to grace recited in Hebrew, even if they do not understand.

Although the responsibilities of these three individuals vis-à-vis Torah Law are less than those of adult freemen, in this instance, they may recite the blessings.

Note, however, the restrictions mentioned in the following halachah.

A person’s failure to learn such a basic prayer as grace is considered an affront to God, since it shows a fundamental indifference to the obligation of serving Him (Rashi, Sukkah 38a).

See Chapter 1, Halachah 2.

A child cannot fulfill the obligations of adults with regard to other blessings, the reading of the Megillah, or Hallel and the like. There is a difference with regard to grace. With grace, the child’s recitation of the blessings of grace comes as a result of a single Rabbinic obligation. Hence, he can fulfill the mitzvah on behalf of an individual whose obligation is also Rabbinic in origin.
In contrast, with regard to other blessings, the blessings themselves are Rabbinic in origin, and the child’s obligation to recite them constitutes a second Rabbinic obligation. Accordingly, he may not fulfill the mitzvah for someone whose obligation stems from a single Rabbinic degree (Tosafot, Megillah 19b).

See Chapter 1, Halachah 1

A person who has eaten to the point of satisfaction, who does not know how to recite grace himself, and is not in the company of another adult, should recite grace together with the child, repeating after him word by word.

See Chapter 1, Halachah 11.
Note the comments of the Ra’avad and the Kessef Mishneh on the following halachah concerning the following question: May an adult who has eaten to the point of satisfaction fulfill his obligation by listening to grace recited by another adult who has not eaten to the point of satisfaction?
The Ra’avad notices that no distinction is made in the Talmud, and it appears (see Berachot 48a, b) that a person who ate only a k’zayit may recite grace for anyone, regardless of how great a meal he ate. Accordingly, rather than contradict the principle stated here, he states—in contrast to the Rambam’s view—that even if one eats only a k’zayit, he is obligated by Scriptural Law to recite grace.
Faced with the same problem, the Ba’al Halachot Gedolot rules that a person who ate only a k’zayit may not recite grace for anyone who ate to the point of satisfaction. Rav Yosef Caro (in all his texts, the Kessef Mishneh, the Beit Yosef, and the Shulchan Aruch, Orach Chayim 197:4) follows the following rationale:
As explained in Chapter 1, Halachah 10 and commentary, because of the principle of areivut (mutual responsibility), it is possible to fulfill one’s obligation by hearing a blessing recited by a fellow Jew, with one exception: blessings that praise God for benefit one enjoys. It is improper for someone who himself does not experience that benefit to utter such praise. The latter point, however, is a Rabbinic ruling and is waived in the instance under discussion, when the person reciting grace has, in fact, partaken of food.

The Rambam’s words are quoted from Berachot 45b. The person responds in this fashion instead of with the usual response, because it praises God, “from Whose bounty we have eaten,” and he has not eaten.
Note Tosafot, Berachot (loc. cit.), which state that one should respond, “Blessed be He, and blessed be His name, continuously and forever.” Their statements are quoted by the Shulchan Aruch (Orach Chayim 198:1). If a quorum of ten people who partook of food is present, a person who did not eat with them should include God’s name in his response (op. cit.).

This response is in place whenever one hears a blessing being recited.