1)

(a)We learn from "Osah" that having relations with a wife's sister does not forbid his wife to him. The reason that we need a Pasuk for this, despite the fact that the Torah does not specifically forbid her, is because - we would otherwise have thought that she is forbidden, since, if in the case of a 'lighter Isur' (Eshes Ish - as we shall see later), the man, who causes his wife to be forbidden, becomes forbidden to take her back, then how much more so in the case of a more stringent one (Achos Ishah), should the woman, who causes her sister to become forbidden to her husband, be forbidden to return to her husband.

(b)According to Rebbi Yehudah, Beis Shamai and Beis Hillel agree that relations with one's mother-in-law forbids his wife to him. They argue over our case (whether he becomes forbidden through relations with his wife's sister. Beis Hillel permit it because of "Osah". Beis Shamai forbid it, a. because of the 'Kal va'Chomer' that we just cited, and b. because they do not hold of the Derashash from "Osah".

(c)According to Rebbi Yosi, on the other hand, Beis Shamai and Beis Hillel both agree that relations with his wife's sister do not forbid her to him, and their Machlokes is - whether relations with his mother-in-law forbid his wife to him or not.

2)

(a)A man who marries a woman forbids his wife more than she forbids him - inasmuch as whereas he forbids her to everyone, she only forbids him to her relatives.

(b)Rebbi Yosi extrapolates from this that if a man has relations with his wife's sister b'Shogeg, she remains permitted to him - because, if his wife (whose Isur is relatively severe) remains permitted after a Bi'as Isur b'Shogeg, then if the man (whose Isur is relatively light) performs a Bi'as Isur (with his wife's sister), then she should certainly remain permitted to him.

(c)Rebbi Ami Amar Resh Lakish learns Rebbi Yehudah's opinion (that relations with a man's mother-in-law forbids his wife to him) from the Pasuk "ba'Esh Yisrefu Oso v'Es'hen" - which, seeing as it cannot possibly come to sentence both women to Sereifah (as we explained on the previous Amud), it must come 'Im Eino Inyan' to teach us that both women become forbidden through relations with his mother-in-law.

3)

(a)Rav Yehudah Amar Shmuel took that man who had relations with his mother-in-law - and gave him Makas Mardus (Malkus mid'Rabanan).

(b)When he told him that if not for Shmuel, he would have forbidden him permanently - he meant that, if not for Shmuel, who ruled like Rebbi Yosi, he would have forbidden him to live with his wife (like the opinion of Rebbi Yehudah).

4)

(a)We learned above that, if not for the Pasuk "Osah" we would have forbidden a woman to her husband on the basis of his having had relations with her sister, from a 'Kal va'Chomer'. Rav Chisda initially learns the 'Kal va'Chomer' from Machzir Gerushaso - referring to when the first husband contravened the Lav (a light Isur) of remarrying his wife, and who now forbids her to return to her second husband (who was the cause of her becoming prohibited to her first husband).

(b)We reject this 'Kal va'Chomer' however, on the basis of the two stringencies that Machzir Gerushaso has over Achos Ishto - 1. that the woman too, contravened the Lav (which is not the case when her husband had relations with her sister), and 2. the prohibition that he contravened a permanent Isur (whereas Achos Ishto only remains in force as long as his wife is alive).

(c)So Resh Lakish learns the 'Kal va'Chomer' from a Yevamah. For two reasons, this cannot mean a Yevamah who had relations with someone from the Shuk; 1. because, unlike Achos Ishto, where the wife herself did not sin, here she did (like we just said with regard to Machzir Gerushaso) - 2. because the Lav of Yevamah l'Shuk forbids her to everybody (whereas that of Achos Ishto only forbids the sister to her husband, but not to anyone else).

5)

(a)So we establish the 'Kal va'Chomer' from Yevamah l'Achim. It is obvious that this cannot be referring to a Yevamah who had relations with someone else (like Rav Hamnuna, who forbids her to the brothers) - because there again, a Yevamah is more stringent than Achos Ishto, inasmuch as firstly, she herself sinned, and secondly, she is forbidden to everyone (neither of which is the case by Achos Ishto - as we pointed out earlier).

(b)The case of Yevamah must therefore be - Yevamah l'Achim, when one brother made Ma'amar, and the second brother, Bi'ah, forbidding her to the one who made Ma'amar, which is an Isur Kal seeing as it is only mid'Rabanan.

(c)We get round the problem that, if that is the case, then the second brother would not need to have made Bi'ah with the Yevamah; she would be forbidden to the first brother even if he just made Ma'amar (like the first one did) - by establishing the Beraisa like Raban Gamliel, who holds 'Ein Ma'amar Achar Ma'amar', in which case it is only Bi'ah that will forbid her on the brother who made Ma'amar, and not Ma'amar.

(d)We cannot reject the current contention (to learn the 'Kal va'Chomer' from Yevamah l'Achim) from Ma'amar, as we just explained. We nevertheless reject it on the grounds that - even if she cannot become forbidden to the first brother through the Ma'amar of the second one, she will however, become forbidden if he gave her a Get or performed Chalitzah (so why does the Tana need to mention Bi'ah?).

6)

(a)So Rebbi Yochanan tries to establish the case by Sotah, not a Sotah with whom ...

1. ... the husband had relations - because here again, it does not require Bi'ah to forbid her on the adulterer, seeing as even a Get would achieve that, or even if he just refused to give her the water to drink (since it must be given to her via the husband).

2. ... the adulterer had relations, and who becomes forbidden to her husband - because that is not a light Isur, but an Isur Eshes Ish (and all the suggestions until now have been ordinary Chayavei Lavin at most).

(b)So Rava and Ravin Amar Rebbi Yochanan finally establish the 'Isur Kal' by Eshes Ish, which is called an Isur Kal - inasmuch as the one who forbids her (her husband) does not necessarily forbid her all his life (in the way that a wife forbids her sister on her husband), seeing as he can permit her to get married by giving her a Get.

7)

(a)Following the Tana Kama's ruling in our Mishnah (regarding the wife who returned after her husband had married her sister), Rebbi Yosi states 'Kol she'Posel al Yedei Acheirim Posel al Yedei Atzmo (v'Chol she'Ein Posel al Yedei Acheirim Ein Posel al Yedei Atzmo)' - meaning that in the case when his brother-in-law (his second wife's husband) arrived too, just as his marriage forbids his brother-in-law to take back his wife, so too, will it forbid him to take back his own wife (mid'Rabanan).

(b)He cannot mean to say the opposite (that just as his own wife is permitted to him, so too, is his brother-in-law permitted to his wife) - because then he should have said 'Kol she'Ein Posel al Yedei Atzmo Ein Posel al Yedei Acherim' (in the second half of his statement and not vice-versa).

(c)Rebbi Yosi concludes 'v'Chol she'Eino Posel al Yedei Acherim, Eino Posel al Yedei Atzmo'. According to Rebbi Ami - he is referring to the Reisha, where he married his sister-in-law through two witnesses. Seeing as there, his brother-in-law is permitted to take his wife back (since she was an Anus), Rebbi Yosi agrees with the Tana Kama that he too, is permitted to take back his (and it is only in the Seifa, which adds the case of marrying through one witness, where his brother-in-law is forbidden to take back his wife, that he disagrees with him).

8)

(a)According to Rebbi Yitzchak Nafcha, Rebbi Yosi refers to the Seifa (to when one witness testified) 'Ha d'Azli Ishto v'Giso, Ha d'Azli Arusaso v'Giso'. If his sister and brother-in-law were betrothed, then we are afraid of people assuming that the first Kidushin was made conditionally, that the condition was not met and that the second marriage was therefore valid. And when they see the woman leaving the marriage without a Get, they will extrapolate that a woman may leave a marriage without a Get. This fear does not exist if they were married, because there is no such thing as a marriage on condition, as we explained earlier.

(b)Now Rebbi Yosi's statement is clear: 'v'Chol she'Eino Posel al Yedei Acheirim' - when his wife and brother-in-law were originally married, in which case we permit his brother-in-law to take back his wife upon their return, seeing as we have nothing to fear, 'Eino Posel al Yedei Atzmo' - he is also permitted to take back his own wife.

(c)The Rabanan disagree with him in the case of one witness, to forbid his brother-in-law to take back his wife even if they were previously married - because, according to them, the reason that a woman who married through one witness is forbidden to return to her husband is due, not to the fear of what people might say, but because of her carelessness in marrying without making the necessary inquiries, as we explained earlier. Consequently, according to them, there is no difference between marriage and betrothal in this matter.

9)

(a)Rav considers a Yevamah like an Eshes Ish. According to Rav Huna - this refers to a woman whom a man betrothed before going overseas. After the man's brother, hearing that he had died, performed Yibum with her, his brother returned. Rav maintains that she has the same Din as a married woman, and is forbidden to return to him.

(b)Rav must be speaking about a woman whom the brother had betrothed - where we are afraid of the unmet condition that people will suspect, going on to assume that the brother's marriage ('Yibum') was therefore valid, and that the first brother is now marrying Eshes Achiv. Had the first brother married her however, then everyone would have known that the second marriage (the 'Yibum') must have been a mistake, in which case there is no room for the above fear.

(c)Shmuel says 'Einah k'Eshes Ish', and she is permitted to return to her husband - because it is unusual for people to think that there must have been an unfulfilled condition ... .

(d)Rav Yosef initially thinks that Shmuel's ruling here clashes with his previous statement where he ruled like Rebbi Yosi - who, in the first part of his statement, does indeed take into account the fear based on the unfulfilled condition.

10)

(a)Abaye gives three possible answers to Rav Yosef's Kashya. Firstly, he answers by establishing Rebbi Yosi like Rebbi Ami - who is not concerned about whether there might have been a condition or not, seeing as, in his opinion, Rebbi Yosi is even strict by 'Ishto v'Giso' too.

(b)And as for the contradiction in the two rulings, we will answer Shmuel like this: By the case of Achos Ishto, she is forbidden to return to her husband - because should his brother-in-law arrive before his own wife, he will immediately be forbidden to take back his wife, who will require a Get, so that people should not say that her first husband divorced her, the second one married her and now she is leaving without a Get (and as for being Achos Ishto, they will say that her sister died, as the husband indeed believed). But in the case of Eshes Achiv, as soon as the brother appears, and takes back his wife, people will not say that he divorced her and the second one married her (because everyone knows that a brother's divorcee is forbidden), but they will think that he had died and that the second brother's marriage was a mistake (as was indeed the case).

(c)Alternatively, Abaye answers the Kashya even according to Rebbi Yitzchak Nafcha's explanation - by restricting Shmuel's ruling like Rebbi Yosi, to the latter part of his statement 'v'Chol she'Ein Posel al Yedei Acheirim Ein Posel al Yedei Atzmo' (where he permits Ishto v'Giso, even though the Tana Kama forbids it), but not to the former part 'Kol she'Posel al Yedei Acheirim Posel al Yedei Atzmo' (where he forbids Arusaso v'Giso), the source of our Kashya.

(d)In another alternative, Abaye dismisses Rav Huna's interpretation of the Machlokes between Rav and Shmuel. He suggests that they argue over Rav Hamnuna's statement - that a Yevamah who committed adultery with another man is forbidden to the Yavam.

11)

(a)According to Rav Hamnuna ...

1. ... when Rav says 'Yevamah Harei Hi k'Eshes Ish' - he means to equate the Din of a Yevamah who commits adultery l'Shuk with that of an Eshes Ish, who becomes Pasul through relations with another man.

2. ... when Shmuel says 'Einah k'Eshes Ish' - he means that she does not have the same Din as an Eshes Ish.

(b)As a final alternative, Abaye explains the Machlokes with regard to the Kidushin of another man taking effect on a Yevamah - according to Rav it does not; according to Shmuel, it does.

(c)True, this dispute was brought above earlier in the Perek. In fact - they only disputed this point once, and the second occasion is brought based on the first.