1)

(a)The Mishnah obligates three people who ate together - to Bensch together as a group ('Mezuman' [where one of them says 'Nevarech she'Achalnu mi'Shelo', as we will see later]).

(b)The Tana lists a number of cases where, for various reasons, we would have thought they cannot Bensch Mezuman. The first of these is D'mai - (whose acronym is 'Da Mai' [What is this?]), crops that one purchases from an Am-ha'Aretz, that Chazal suspect, he may not have Ma'asered.

(c)We would have thought that the person who ate D'mai cannot participate in Mezuman (see Tosfos Yom Tov & Tiferes Yisrael at the end of the Mishnah) - because it is a 'Mitzvah ha'Ba'ah ba'Aveirah'.

(d)It is not a 'Mitzvah ha'Ba'ah ba'Aveirah' however - because even though he should not have eaten it without first taking Ma'aser, it is not considered as if he ate Tevel, since the majority of Amei-ha'Aretz tend to separate Ma'aser (see Tosfos Yom Tov).

2)

(a)The list also includes Ma'aser Rishon she'Nitlah Terumaso, Ma'aser Sheini and Hekdesh that were redeemed and a Shamash who ate a k'Zayis. The significance of 'Ma'aser she'Nitlah Terumaso' is - that although its Terumah (i.e. T'rumas Ma'aser that the Levi separates from his Ma'aser) has been taken, Terumah Gedolah has not.

(b)And the reason that it is not a Mitzvah ha'Ba'ah ba'Aveirah is - because the Torah permits a Levi who arrives in the field before the Miru'ach (the flattening of the heap that renders the crops Tevel) to take Ma'aser even though Terumah has not yet been taken.

3)

(a)Even though in the second case, the Ma'aser Sheini and Hekdesh have been redeemed, the Tana is coming to teach us - that the redemption is valid, even if the owner failed to add the required fifth (which he still remains obligated to do).

(b)In the third case (a Shamash who ate a k'Zayis), he is coming to teach us - that even though the Shamash walks around during the meal, he is still considered a member of the group and can participate in the Mezuman.

4)

(a)The last case in the list is a Kuti - a member of a sect that Sancheriv brought from Bavel (see Tosfos Yom Tov) and Kuta and from other lands, whom he settled in the cities of Shomron, and who converted out of fear, after suffering a plague of lions because they continued to practice idolatry in Eretz Yisrael (see also Tosfos Yom Tov). They subsequently kept the written Torah but not the oral one.

(b)Despite the fact that they did not keep all the Mitzvos properly, the Mishnah nevertheless permits them to participate in a Mezuman - because those Mitzvos that they kept (including that of Birchas ha'Mazon), they kept meticulously.

(c)Eventually, the Chachamim gave them the status of Nochrim in all regards ...

(d)... when they discovered them worshiping the image of a dove on Har Gerizim.

5)

(a)The first item in the Mishnah's second list is Tevel - crops from which T'rumos and Ma'asros have not yet been taken.

(b)The acronym of 'Tevel' is - 'Tav Lo' (no good).

(c)There - the Mishnah disqualifies the person who ate it from participating in Mezuman (see Tiferes Yisrael, note 12).

(d)And what the Tana is coming to teach us is - that he is not eligible to participate in a Mezuman, even though he ate only Tevel de'Rabbanan ...

(e)... such as crops that grew in a plant-pot that has no hole in its base (see Tosfos Yom Tov).

6)

(a)In this list, the Mishnah includes Ma'aser Rishon she'Lo Nitlah T'rumaso, Ma'aser Sheini and Hekdesh that were not redeemed and a Shamash who ate less than a k'Zayis. 'T'rumaso', in the first case - means Terumah Gedolah (not like we learned in the Reisha).

(b)The case is - where the Levi arrived in the field for his Ma'aser after the Miru'ach has taken place, and the Tana is coming to teach us that, in this case, should the owner give it to him before separating Terumah Gedolah, what he gives him remains Tevel.

(c)In the second case even though technically, the Ma'aser Sheini and the Hekdesh were redeemed, the person who ate it cannot participate in the Mezuman- because the Tana is speaking in a case where the former was redeemed with unminted coins, and the latter, with Karka (in which case, the redemption is invalid).

(d)And the Tana only inserts the case of a Shamash who ate less than a k'Zayis - to balance the equivalent case in the Reisha, where he ate a k'Zayis, even though there is no Chidush (in the Seifa).

7)

(a)The Mishnah - adds a Nochri (who has already circumcised, but not yet Toveled) to the above list ...

(b)... to teach us that until he Tovels he is still considered a Nochri.

8)

(a)The group of three that the Mishnah now lists that cannot participate in Mezuman is - women, Avadim Cana'anim and Ketanim.

(b)The Gemara permits a Katan Pore'ach' to Bensch Mezuman. Some interpret Katan Pore'ach as a Katan who knows to whom he is Bensching. Others - disqualify all Ketanim from particating in Mezuman, unless they have turned thirteen (when they are permitted to participate even if no pubic hair has yet grown.

(c)The Yerushalmi however - disqualifies all Ketanim from participating in Mezuman.

9)

(a)A group of women or Avadim is permitted to Bensch Mezuman - provided the participants are all either one or the other.

(b)They cannot combine - because of 'P'ritzus' (immodesty, and its consequences [see also Tosfos Yom Tov]).

(c)According to the Tana Kama, someone who has eaten a k'Zayis may join a Mezuman. R. Yehudah - requires a k'Beitzah (see Tosfos Yom Tov).

(d)The Halachah - is like the Tana Kama.

10)

(a)When there are three people Bensching, the Mevarech says ' ... Nevarech al ha'Mazon she'Achalnu mi'Shelo'; when there are ten, he says - ' ... Nevarech l'Elokeinu (see Tosfos Yom Tov) al ha'Mazon she'Achalnu mi'Shelo'.

(b)When there are a hundred people, the Mevarech says 'Nevarech la'Hashem Elokeinu ... ', when there are a thousand, he says - Nevarech la'Hashem Elokeinu Elokei Yisrael ... '.

(c)When there are ten thousand participants, the Mevorech says 'Nevarech la'Hashem Elokeinu Elokei Yisrael Elokei ha'Tzevakos Yoshev ha'Keruvim al ha'Mazon she'Achalnu mi'Shelo. According to this Tana, in all of the above cases if there is one more participant more than the specified number - instead of 'Nevarech', he says 'Barchu ... ' (see Tosfos Yom Tov DH 'Nevarech l'Elokeinu') ...

(d)... seeing as there the required number of participants are present without him.

11)

(a)The author of the above rulings is R. Yossi ha'Gelili, who derives these distinctions from the Pasuk in Tehilim - "be'Makheilos Barchu Elokim" (implying that the text of one's praise of Hash-m depends upon the number of participants [see Tosfos Yom Tov]).

(b)The name of the Tana who disagrees with him is - R. Akiva, who maintains that the text of Mezuman is fixed ...

(c)... like we find in Shul - where we say 'Barchu ... ', irrespective of how many congregants there are.

(d)The Halachah is - like R. Akiva.

12)

(a)The only distinction the Mevarech therefore draws is between less than ten people Bensching and more than ten (following the text that we cited above). When there is ...

1. ... no Minyan, the participants respond - 'Baruch she'Achalnu mi'Shelo u've'Tuvo Chayinu'.

2. ... a Minyan, they respond 'Baruch l'Elokeinu she'Achalnu mi'Shelo u've'Tuvo Chayinu'.

(b)According to R. Yishmael (like whom we rule), the Chazan in Shul says 'Barchu es Hash-m ha'Mevorach'. R. Akiva cites the text as - 'Barchu es Hashem' (see Tosfos Yom Tov [Ibid.] quoting the Yerushalmi).

13)

(a)The Mishnah - forbids three people who ate together to split up for Bensching (see Tosfos Yom Tov) ...

(b)... since they have become subject to Zimun, they are all obligated to carry it out.

(c)The smallest number of people that are permitted to Bensch separately is - six (who may divide into two groups [see Tosfos Yom Tov]).

(d)Whereas the smallest number that are ...

1. ... forbidden to break up after six is - ten (in order to Bensch with a Minyan, as we learned above).

2. ... permitted to break up after ten is - twenty because every participant has become obligated to Bensch with a Minyan.

14)

(a)Two groups of people who are eating in the same room are permitted to combine if they are being served by the same Shamash (and even if they are not) - as long as at least one from each group can see one from the other group.

(b)R. Eliezer rules that one may only recite 'Borei P'ri ha'Gafen' after diluting it with water - because their wine tended to be too strong to drink.

(c)Otherwise, one recites over it - 'Borei P'ri ha'Eitz.

(d)According to the Chachamim - one recites 'Borei P'ri ha'Gafen' even before it has been diluted.

(e)The Halachah is - like the Chachamim.