- Why both cases of two brothers and one brother were taught
The Mishnah on Daf 26a had stated that in a case of two sisters falling to two brothers for yibum, if one of the sisters is an ervah to one of the brothers, then that brother is forbidden to take her, but is permitted to take her sister in yibum. The Gemara asks why this was taught when we already learned it in the Mishnah on Daf 20a, with the case of two sisters who fall to one brother and one of the sisters is an ervah to the yavam, and the Mishnah states: אחותה כשהיא יבמתה או חולצת או מתיבמת – her sister, who is her fellow yevamah, may either do chalitzah or be taken in yibum. Why did our Mishnah need to repeat it? The Gemara answers that both cases were needed, for if only the case of one yavam was taught, one might think that in the case of two brothers, איכא למיגזר משום שני – there is room to think that a gezeirah should be made that the first brother not do yibum, for otherwise his doing yibum might lead to the second brother mistakenly doing yibum. Therefore, the Mishnah is teaching that the first brother may do yibum. And if only the case of two brothers was taught, one might think that the first brother can do yibum, since the second brother shows that one may not take a sister of a zekukah. But in the case of one yavam, where there is no second brother, one might come to think that one is permitted to take a sister of a zekukah in yibum, without realizing the second sister was an ervah to the yavam.
- Which cases in the first Mishnah does Rebbe Chiya’s rule apply?
Rav Yehudah said in the name of Rav, and similarly, Rebbe Chiya taught a Baraisa which states: Concerning all of the arayos listed in the first Mishnah of the Masechta, I can apply the Mishnah’s teaching that: האסורה לזה מותרת לזה – the sister who is forbidden to this brother is permitted to that brother, and vice versa, and this is a case in which they stated: אחותה כשהיא יבמתה או חולצת וא מתייבמת – her sister, who is her fellow yevamah, may do chalitzah or be taken in yibum. Rav Yehudah said that this statement applies to all the arayos listed in the first Mishnah, from the case of “mother-in-law” and onward, but does not include the first six cases related to daughters and granddaughters. The reason is that this rule could only apply to daughters that were conceived out of wedlock, for then they could be two sisters that were daughters from two brothers from the same woman, and our Mishnah only deals with cases of marriage, not with cases where a woman was violated. The Gemara brings two more interpretations of this rule.
- Rebbe Shimon’s source that there is no chiyuv yibum or chalitzah for a relative of a zekukah
The next Mishnah states that if there were three brothers, two of whom were married to two sisters, or to a woman and her daughter, or her granddaughter, and both married brothers died childless, the yevamos require chalitzah and may not be taken in yibum. This is because each widow is a relative of his zekukah. They must be do chalitzah, since the issur of taking a relative of a zekukah is only a d’Rabbanon. But Rebbe Shimon exempts them even from chalitzah. The Gemara brings a Baraisa that taught: Rebbe Shimon exempts them both from chalitzah and yibum, for the passuk states: "ואשה אל אחתה לא תקח לצרור" – You shall not take a woman in addition to her sister to make them tzaros. This teaches, בשעה שנעשו צרות זו לזו לא יהא ליקוחין אפילו באחת מהן – that at the time that two sisters become tzaros to one another, by falling to the same man for yibum, you shall not have a marital bond with even one of them.
