Talmud Brachot Top Ten Teachings, Daf 45:

1. A few laws about the zimun. As long as a meal is ongoing additional brachot are not needed on additional food, but once the meal has officially ended one would need to make a new bracha to start eating more. As a meal is winding down, there are certain signposts that signal the halachic end of the meal. One of those signposts is the zimun. The mishna says that when three people eat a meal of at least a kezayit (according to one opinion, a little less than an ounce) of bread together, they must make a zimun, a formal invitation to bircat hamazon. The simplest understanding of zimun is that we are preparing to do the mitzvah of bircat hamazon. Two people eating together are not required to do a zimun, and there is a debate about whether or not they are allowed. The mishna says that women can do a zimun for themselves but cannot mix with men. They can join in if men are making a zimun, but they cannot be counted for the minimum of three. When at least ten men are present, the word “Elokeinu” is added to the text of the zimun.
2. The source for the zimun. There is a debate among the rishonim regarding whether the mitzvah of zimun is Biblical or rabbinic. According to Rav Asi, the obligation is based on the verse, “Gadlu laHashem iti uneromema shemo yachdav” – Declare the greatness of G-d with me, and we will exalt His name together. But it’s possible that this verse is an asmachta – support for a rabbinic obligation, rather than a true Biblical commandment. Rav Avahu suggests a different verse as the source: “Ki shem Hashem ekra, havu godel l’Elokeinu” – When I call out the name of G-d, ascribe greatness to our G-d. The word “havu” (ascribe) is written in the plural form, suggesting that one person is calling at least two others to join with him in ascribing greatness to G-d. While neither verse makes any specific reference to bircat hamazon or the zimun, it is easy to understand why the rabbis make this association. When do we “declare the greatness of G-d” or “ascribe greatness to our G-d”? When we make a bracha. The verses could be referring to any time we bless G-d, but it makes more sense to connect them to an explicit mitzvah, and according to most opinions bircat hamazon, the blessing we make after eating, is the only Biblically-mandated bracha. Nonetheless, the majority opinion is that the mitzvah of zimun is rabbinic and the verses that prove the requirement to do zimun are asmachtos that support the rabbinic obligation.
3. G-d recognizes human limitations. Rabbi Shimon ben Pazi says there used to be a person in the synagogue whose job was to translate the Torah reading, verse by verse, into Aramaic for the sake of the congregation. How do we know that this translator should not raise his voice louder than the Torah reader? From the verse, “Moshe yedaber veha’Elokim ya’anenu bekol” – Moses would speak, and G-d would respond to him in his voice. “Bekol” – in his voice – teaches that G-d responded with the same level of voice as Moses. When did this happen? When we received the Ten Commandments at Mount Sinai. Most authorities hold that after the first two commandments, the rest were given to us by Moses rather than directly by G-d. But using this as the proof text for the law that the interpreter shouldn’t raise his voice louder than the Torah reader implies that G-d was Moses’s interpreter at Mount Sinai. Tosfot disagrees with this idea, saying that of course, G-d is the originator of the Ten Commandments and Moses was His interpreter. Therefore, according to Tosfot, the proof text is not very strong and needs to be explained in a different way. But the Mei Hashiloach says that G-d really was, in a sense, Moses’s interpreter in that moment. Moses was speaking, and G-d was helping the people internalize what he was saying. G-d opened our hearts so that the words of the Torah that Moses spoke could enter us. Still, isn’t that even greater than what Moses was doing? No, because G-d made sure that His voice didn’t surpass Moses’s. He limited what He gave us, making Himself “equal” to Moses. If He hadn’t, then we would have surpassed Moses, and G-d didn’t want that. He doesn’t want us to be anything other than what we are. The holiness of that event, when we stood at the foot of the mountain and heard G-d’s voice, could have transformed us if G-d had more powerfully internalized the Torah within us. But instead, G-d limited Himself to match the way Moses spoke to us, to match our human limitations and avoid changing us in a way that would take away our free will.
4. Do two people make a zimun? If two people eat a meal together, they are not required to do a zimun. But are they allowed? The Yerushalmi says that this issue is already debated in Sanhedrin, where we find a machloket about the formation of a beis din. Generally a minimum of three people are required to form a beis din. But what if the third judge doesn’t show up and we only have two? One opinion says that while this is not ideal, the judgment of this two-person beis din is still law. Another opinion says that with only two people it is not a beis din at all. Why would three be needed for a beis din? In some cases, each litigant picks one judge, and those two judges together pick a third. It’s likely that, even unintentionally, the first two judges would be at least slightly biased towards the litigant they were selected by. The third judge is the only one who is truly impartial. Thus a minimum of three is always needed; the goal cannot be accomplished with fewer. So when it comes to zimun, does it work with two people, despite being less than ideal, or is there no such thing as a zimun with fewer than three people? The halacha is that three are always required.
5. Fulfilling a mitzvah through a sin. The mishna says if you’re eating bread but didn’t do the things required to make it kosher (such as terumah and ma’aser), you do not make a zimun. Do you still make a hamotzi and say bircat hamazon for this bread? The underlying question here is about how to handle a mitzvah haba ba’averah – a mitzvah that comes about through a sin. For example, can you steal a lulav and shake it on Sukkot? Tosfot notes that this discussion cannot be limited to one all-inclusive principle derived from one single verse, but includes many verses and many laws. Why? The Mei Hashiloach says that we must think of mitzvot like spiritual or ethical medicine. A mitzvah treats something in your soul and blocks something bad from happening. In order for this spiritual or ethical medicine to work, we have to do the mitzvah in the right way. But every mitzvah is different. Each one has specific criteria that must be adhered to in order for its particular spiritual healing power to take effect. The mitzvah of lulav, for example, specifically represents using what is yours and not taking what isn’t yours. That mitzvah, by definition, cannot be completed with a stolen lulav. We need separate discussions and rulings for how to handle each specific mitzvah that may come about through a sin, because we must consider the specific meaning and qualities of each mitzvah. When it comes to food that we are not permitted to eat, the Rambam holds that no brachot should be made before or after eating. The source for this opinion is in the Yerushalmi. The Raavad disagrees, saying that while zimun is not required in this situation, brachot before and after eating are still required. This opinion contradicts not only the Yerushalmi but also an opinion of Rabbi Eliezer ben Yaacov cited in Bava Kama 94a. Why would the Raavad go against the Yerushalmi and Bava Kama? Because the mishna here implies that the brachot are required. If they weren’t, the mishna would not need to single out the zimun. The Raavad sees the brachot and the zimun as two completely different mitzvot, to which we must apply different rules. A bracha is always required before and after eating, because in order to benefit from something in this world we must praise and thank the Creator. Even if the thing you’re benefitting from is technically forbidden, such as non-kosher food, you still owe thanks to G-d. Zimun, on the other hand, has nothing to do with benefitting from the food. The zimun is about preparing for the mitzvah of bircat hamazon and joining together with other people to praise G-d. This is something that should not be accomplished through a sin. Therefore, when the food is forbidden, zimun is inappropriate.
6. A story from the Zohar. A young boy was challenging the students of Rabbi Shimon bar Yochai. He said that they weren’t washing their hands properly before eating bread. When they said, “Let’s bentsch,” he said to them, “You did good by saying ‘let’s bentsch,’ because G-d isn’t blessed in this bracha.” Food is tied to the yetzer hara, because when we enjoy the physical world there is always a fear that we’ll enjoy it too much and fall into unholiness. Making a bracha before eating activates the spiritual aspect of the food and keeps us from falling into this trap, thus allowing us to eat the food. But the after-blessing is more complicated, because there is no food to activate. Therefore the after-blessing needs a special invitation.
7. Women and zimun. When women eat on their own, without men, are they required to make a zimun? There is a machloket among the Rishonim. Some say women are obligated, others say women are allowed but not required. The Aruch Hashulchan says that in our days we don’t see women doing this. But today, there are women who do. If there are ten women, should they add the word Elokeinu? Probably not, but there are sources that suggest they should. Can women and men eat together and count up to three or ten in total for a zimun? Most people today don’t, though there is a halachic source that might allow it. This is an evolving question in modern Orthodoxy today, so you should consult your own rabbi.
8. Why would women do zimun? We know that women can’t be counted for a minyan. So why would women make a zimun? Perhaps the zimun has a different halachic standard than a minyan. We have already seen the comparison of zimun to beis din, so perhaps we can use the beis din standard of deyos. Women have minds and opinions, so they can be counted for this. Three people means three opinions. The Mei Hashiloach says that when you have three people together, at least one of them will know something. This applies to both men and women.
9. When not everyone is ready. If two of the three people are finished with their meal, they can tell the third person to stop eating and answer to the zimun. The third person should answer to the zimun and listen to part of bircat hamazon, and then he can return to his meal. But if only one person is finished and two are still eating, he cannot ask them to pause and do zimun with him. Keep in mind that people used to literally do bircat hamazon together, with the leader reading the whole thing for everyone. That’s a major interruption for someone who isn’t done with his meal. Interrupting one person in this way is acceptable, but for one person to interrupt two others would be inconsiderate. A story is told of Rav Papa, who ate a meal with his son and his friend. His son was ready for zimun but Rav Papa and his friend weren’t, so Rav Papa interrupted his meal to let his son do the zimun. In this story two people stopped for the sake of one, which we just said should not be done. But Rav Papa was going beyond the letter of the law for the sake of his son. He did not have to, and the rule is that two do not need to stop for one.
10. Three rabbis who made a mistake. Three rabbis were eating together and did not make a zimun because they thought it was not necessary. But why would they think that? In our daily davening we find an important principle: the angels request permission from one another before proclaiming G-d’s holiness. If angels must request permission, how can men not? Perhaps the answer is that among angels there is a hierarchy, while these three rabbis were all on the same level. Usually the head of the group is the leader of the zimun, but with three equal rabbis there was no clear leader, so they thought there was no need for one person to lead the bircat hamazon. They all bentsched on their own, but then they worried that they had done the wrong thing. They asked another rabbi, and he confirmed that they had made a mistake. They’d fulfilled their obligation of bircat hamazon but had not fulfilled their obligation of zimun. Their mistake was in not realizing that the zimun is about more than just honoring one another. It’s about joining together and preparing for the mitzvah of bircat hamazon. A mitzvah should not be done without preparation, and the best way to prepare for the mitzvah of bircat hamazon is to invite each other to participate.