1)

(a)Even though the initial obligation to perform Mitzvah lies with the oldest brother, the Mishnah rules that if a younger brother performs Yibum without permission - his Yibum is valid.

(b)We learn 'Mitzvah b'Gadol l'Yabem' - from "v'Hayah he'Bechor".

(c)We learn from the Pasuk in Ki Setzei ...

1. ... "Asher Teled" - that an Aylonis is Patur from Yibum.

2. ... "v'Lo Yimacheh Sh'mo mi'Yisrael" - that the wife of a eunuch does not require Yibum.

2)

(a)We learn from the Pasuk there "Yakum al Shem Achiv" - that, whichever brother performs Yibum, inherits all the property of the deceased brother.

(b)The Torah cannot mean that the son who is subsequently born should be called by the same name as the deceased brother - because we learn from the Gezeirah-Shavah "Yakum Al Shem Achiv" (here) and "Al Shem Acheihem Yikar'u b'Nachalasam" (in connection with Efrayim and Menasheh) that the Pasuk is referring to inheritance.

(c)Regarding this Derashah - Rava tells us that this is the only place in the Torah where the Derashah (the Gezeirah-Shavah) is accepted and the simple explanation ignored.

(d)If not for the Gezeirah-Shavah, the Torah would be teaching us that the baby that is born to them should be called after his deceased uncle. If the Torah was speaking to the Yavam, it ought then to have written "Yakum al Shem Achicha"; If to the Beis-Din, it ought to have to have written "Yakum al Shem Achi Aviv". In fact, the Torah would be speaking to the Beis-Din, and instructing them to tell the Yavam how he should name his first-born child.

3)

(a)In spite of the fact that the Torah writes "Bechor", we know that it is not confined specifically to the first-born - because otherwise, why would the Torah need to preclude Eishes Achiv she'Lo Hayah b'Olamo from Yibum (seeing as he is obviously not the first-born).

(b)Nor can 'Eishes Achiv she'Lo Hayah b'Olamo' refer to a maternal brother - because the Torah connects Yibum with inheritance (as we have already learned), so it must be a paternal Bechor who performs Yibum, and not a maternal one who does not inherit.

(c)We learn from "Bechor" - that it is the oldest paternal brother who has the initial onus to perform Yibum.

4)

(a)We know that the Torah does not write "Bechor" to tell us that when there is a Bechor, the Mitzvah takes place (with any of the brothers), and when there is not, there is no Mitzvah - because the Torah writes "u'Mes Achad Meihem", implying whichever of the brothers dies, even if it is the oldest, and it goes on to say that the Bechor should perform Yibum.

(b)The Pasuk of "u'Mes Achad Meihem" cannot be speaking when the younger brother died, and it is the Bechor who performs Yibum - because if that were so, back comes the Kashya why would the Torah then need to preclude Eishes Achiv she'Lo Hayah b'Olamo from Yibum?

(c)Nor can we say that - when there is no Bechor, then a younger brother who performed Yibum may retain his Yevamah, but when there is, then it is only the oldest brother who can perform Yibum - because the Torah writes "Ki Yeshvu Achim Yachdav", rendering all the brothers eligible to perform Yibum.

5)

(a)Abaye Keshisha cites a Beraisa 'Mitzvah b'Gadol l'Yabem; Lo Ratzah, Holchin Etzel Achiv ha'Katan; Lo Ratzah ... ' , by which he means - that the initial Chiyuv lies on the oldest brother, then the obligation passes on to the second oldest, and so on (see also Tosfos DH 'v'Im').

(b)This proves that - even when there is no Bechor, the initial obligation lies on the oldest brother.

(c)We cannot learn this from the previous words 'Mitzvah b'Gadol l'Yabem' - because that could be referring to the Bechor (and we are speaking here specifically when there is no Bechor). Otherwise, we would have brought the proof from the Mishnah in ha'Choletz 'Lo Ratzah, Chozrin Etzel Gadol'.

(d)And we know that even if another brother other than the Bechor performs Yibum, he still takes his deceased brother's property - because the Torah writes "Yakum al Shem Achiv", which he did.

6)

(a)In spite of the fact that there is no practical difference between a Bechor and the oldest brother who is not a Bechor, the Torah nevertheless refers to the oldest brother as "Bechor" to teach us - that (like a Bechor regarding his extra portion) the Yavam only receives the inheritance that is available from their father at the time of his brother's death, but not what the father will only obtain later - see also Hagahos ha'Gra.

7)

(a)Our Mishnah prohibits someone who is suspected of having had relations with a Shifchah from marrying her when she is set free, and the same applies with regard to a Nochris who converts - because he creates a bad name for himself, by substantiating the rumor.

(b)Should he nevertheless marry her illegally - he is not obligated to divorce her .

(c)On the other hand, someone who is suspected of adultery with a married woman is obligated to divorce her, in the event that he marries her after her divorce - because, as opposed to the previous case, which is only mid'Rabanan, in this case, it is the Torah that forbids the adulterer (as well as the woman's husband), to live with her.

8)

(a)Rebbi Nechemyah - declares invalid the conversion of a man who converted in order to marry a bas Yisrael, or vice-versa.

(b)He also disqualifies conversions for reasons of wealth, prestige, terror of wild animals, superstition or fear of retaliation. When he says 'ad she'Yisgayru bi'Zeman ha'Zeh' he means - that their conversion is only valid, if they converted when Yisrael were downtrodden, like they were in his days.

(c)Our Mishnah implies that the conversion of a Nochri who converts for one of these reasons is legal - because it forbids a man from marrying a woman with whom he is suspected of having had an affair, should she subsequently convert, insinuating that her conversion is nevertheless valid.

(d)Rav is quoted as ruling like the Rabanan of Rebbi Nechemyah, who validate all of the above conversions - in which case, the author of our Mishnah must be the Rabanan.

9)

(a)Rebbi Elazar learns from the Pasuk "Hen Gor Yagur Efes m'Osi; Mi Gar Itach Alayich Yipol" - that it is only those Nochrim who converted when Yisrael are downtrodden, who will join them in Olam ha'Ba.

10)

(a)According to Rav, our Mishnah (which requires the suspected adulterer to divorce the woman, if he subsequently married her) speaks when there are witnesses that he committed adultery with her. Rav Sheshes comments - that Rav must have been asleep when he said this.

(b)He attempts to refute Rav's statement - from the Beraisa which permits the suspected adulterer to remain with the woman, if she first married someone else and was then divorced from him. But surely, if there were two witnesses, the woman would remain forbidden to the adulterer even if she did! Consequently, the Tana must be speaking when two witnesses did not witness what took place, and we can now infer that, had someone else not married her, she would be forbidden, in spite of the absence of two witnesses (contrary to Rav's opinion).

(c)We reject this however, by pointing out that the Tana needs to add that someone else married her first - to teach us that even though someone else married her first, the adulterer is nevertheless forbidden to marry her l'Chatchilah (and not to insinuate that, had someone else not married her, she would be forbidden to him).

11)

(a)If the suspected adulterer subsequently married the woman after her divorce, and had children from her, he would not be obligated to divorce her - so as not to brand her children as Mamzerim.

(b)This concession will not apply however - in the event that two witnesses testify that she was guilty of adultery.

(c)We now establish our Mishnah - when there were children born of their illicit relationship, to conform with Rav's initial statement (that it speaks when there were witnesses).

(d)What forces Rav to establish our Mishnah when children were born from there and therefore when there were witnesses - is the Lashon 'Hotzi'uhah', implying that Beis-Din forced her to separate from her husband, and not the husband of his own volition (for then the Tana should have written 'Hotzi'ah'), and Beis-Din will only force a man to divorce his wife when there are witnesses.

12)

(a)Alternatively, Rav will establish the Beraisos that obligate the adulterer to divorce the woman, even though there are no witnesses (unless she had first married someone else) - like Rebbi (whereas he holds like the Rabanan).

(b)Rebbi rules that if a husband arrives home and finds a peddler leaving the house, and his wife getting dressed - he is obligated to divorce her (see Tosfos DH 'Amar'), because all the evidence is there.

(c)Similarly, he says - if the husband finds the peddler leaving his house, and spittle on the roof of the four-poster bed, or shoes facing inwards so that the identity of the owner should remain hidden, he must divorce her, too.

(d)In the latter case, we cannot just check whose shoes they are - because we are not speaking when there were actually shoes there, but a mark in the dust where the inverted shoes had been.