QUESTION: The Beraisa teaches the source for the prohibition against performing Yibum with the Tzarah of "Achos Ishto" (the sister of one's wife). The Beraisa states that the prohibition is derived from the extra phrase in the verse, "Lo Sikach li'Tzror" -- "[A woman and her sister] you shall not marry to cause them to quarrel" (Vayikra 18:18). The additional phrase "li'Tzror" in the verse teaches that one may not marry the Tzarah of a woman who is an Ervah to him even in a situation of Yibum (as derived from the Gezeirah Shavah of "Aleha").

The Beraisa inquires about the source for the prohibition against marrying the Tzarah of a Tzarah of an Ervah. The Beraisa answers that the source is the verse's usage of the word "li'Tzror" and not "la'Tzur" (with one Reish).

Why does the Beraisa need to derive the prohibition against marrying the Tzarah of a Tzarah from a verse? Once the Torah prohibits the Tzarah herself from doing Yibum (because she is the Tzarah of an Ervah), she remains forbidden to her husband's brothers because of the prohibition of "Eshes Ach" (the wife of one's brother). Accordingly, her status is the same as that of any other Ervah, and her Tzarah should be no different from any Tzarah of an Ervah.

Although the Isur Ervah in this case is that of "Eshes Ach" which normally is suspended in a situation of Yibum, the Mishnah teaches in another case ("Eshes Achiv she'Lo Hayah b'Olamo") that the prohibition of "Eshes Ach" is able to prohibit the woman to the brother with whom she otherwise would have performed Yibum, and the Gemara does not find it necessary to seek a source for this. In that case, a brother born after the death of his older (and childless) brother may not perform Yibum, because he was "not in the world at the same time" as his brother and thus his brother's wife remains forbidden to him as an "Eshes Ach." Similarly, her Tzarah is also forbidden to him because she is the Tzarah of an Ervah. Just as the Gemara needs no source for the prohibition of the Tzarah of an Ervah in this case, it should need no source for the prohibition of the Tzarah of a Tzarah. In fact, RASHI (DH v'Eshes Achiv) compares the exemption from Yibum of the Tzarah of a Tzarah to the exemption of Tzaras "Eshes Achiv she'Lo Hayah b'Olamo." Why, then, does the Gemara seek a scriptural source for this prohibition?

Moreover, when Rashi later (8b) discusses the opinion of Rebbi -- who finds another source for the exemption of a Tzarah from Yibum but gives no source for the exemption of the Tzarah of a Tzarah -- he says that Rebbi does not need a verse to teach that the Tzarah of a Tzarah does not perform Yibum "because she is the Tzarah of an Eshes Ach" (DH Im Ken)! Why does the Gemara here need to prove from a verse that the Tzarah of a Tzarah is exempt from Yibum? (REBBI AKIVA EIGER)

(a) The Gemara itself cites an opinion which concurs with Rebbi Akiva Eiger's question and maintains that no verse is needed to teach that the Tzarah of a Tzarah may not perform Yibum. The Gemara (13a) asks, "How do we know [that the Tzarah of a Tzarah does not perform Yibum]? Rav Yehudah says that we learn it from the word 'li'Tzror.' Rav Ashi says that it is logical [and no verse is needed]." Rav Ashi clearly follows the logic which underlies Rebbi Akiva Eiger's question.

Why, though, does the Gemara there seek a source for the prohibition of Yibum with the Tzarah of a Tzarah when the Beraisa here (3b) clearly states that the source is the verse "li'Tzror"? Moreover, what permits Rav Ashi, an Amora, to argue with the Beraisa and suggest a different source for the prohibition?

The VILNA GA'ON (Hagahos) points out that the text of the Gemara of many Rishonim does not include the Beraisa's statement about the Tzarah of a Tzarah. According to their Girsa, there clearly is no question on the Beraisa or on the words of Rav Ashi, since neither one says that a verse is needed to teach the prohibition of Yibum with the Tzarah of a Tzarah. Rather, the question is on the view of Rav Yehudah: why does he argue with Rav Ashi and suggest a scriptural source for the prohibition?

The RITVA (13a) writes that Rav Yehudah agrees with Rav Ashi that no verse is needed to teach this prohibition. He mentions the verse only as a scriptural support for the logic which prohibits the Tzarah of a Tzarah (like an "Asmachta"). Rav Ashi merely explains what Rav Yehudah actually means; he does not argue at all. Hence, Rebbi Akiva Eiger's question poses no difficulty, even according to Rav Yehudah.

However, many other Rishonim do not agree with the Ritva's approach. Rashi here (3b, DH li'Tzror, and 2b, DH Kach Tzaras Tzarasah) clearly understands that Rav Yehudah derives the prohibition from the verse and not from logic.

In addition, TOSFOS (2a, DH Ad Sof) explains that the text of the Beraisa should include the words about the Tzarah of a Tzarah, and that both Rav Yehudah and Rav Ashi agree that the source for the prohibition of Yibum with the Tzarah of a Tzarah is the verse of "li'Tzror." The dispute later (13a) is only whether or not the prohibition of the secondary Tzaros applies ad infinitum ("Ad Sof ha'Olam"); the prohibition of Yibum with those additional Tzaros is derived from logic (Rav Ashi) or from a verse (Rav Yehudah). According to Tosfos, Rebbi Akiva Eiger's question applies to both Rav Yehudah and Rav Ashi. Why do the Amora'im require a verse to teach the prohibition of Yibum with the Tzarah of a Tzarah?

(b) The verse does not teach that the Tzarah of the Ervah does not fall to Yibum at all and has no "Zikas Yibum" whatsoever. Rather, it teaches only that the brother may not do Yibum with the Tzarah, and that she is prohibited to him with a punishment of Kares (8a). Whenever an Isur Kares stands in the way of performing Yibum, Chalitzah is also prohibited, as the Gemara later (20a) mentions (see also Rashi 2b, DH v'Eshes Achiv). Hence, the brother may perform neither Yibum nor Chalitzah with the Tzarah of the Ervah.

If he is the only surviving brother, there is no Zikah of Yibum whatsoever (for, otherwise, the Tzarah would never be able to remarry, because she is Zekukah to Yibum but cannot do Yibum or Chalitzah). Rather, since the brother is unable to perform either act, there is no Zikah and the woman may remarry.

However, when there are other surviving brothers, perhaps the Zikah takes effect on the entire household as a whole; once she is Zekukah to some of the brothers, she is also Zekukah to all of them. One brother -- the one to whom this woman is an Ervah or the Tzarah of an Ervah -- is unable to remove the Zikah by performing Yibum or Chalitzah. Any of the other brothers, however, may perform Yibum or Chalitzah and thereby remove the Zikah from the entire household -- and also remove the prohibition of "Eshes Ach" for all of the brothers. Just as he removes the Zikah from the other brothers, he also removes the Zikah from the brother who could not do Yibum. Since the Tzarah of the Ervah was Zekukah to that brother, she will not become prohibited to him with the Isur of "Eshes Ach." She will be like any other woman who is able to fall to Yibum more than once (such as when the first brother who married her died childless, and then the second brother who married her through Yibum died childless, and so on). (In other words, this woman is considered to be an "Eshes Ach b'Makom Mitzvah," in which case the Isur of "Eshes Ach" does not stand in the way of doing Yibum.)

Accordingly, the verse is needed to teach that the Tzarah of a Tzarah is prohibited and that there is no Zikah whatsoever (for the Ervah or for the Tzarah) to the brother who is related to them as an Ervah.

This differs from the case of "Eshes Achiv she'Lo Hayah b'Olamo." In that case, no verse is needed to teach that there is no Zikah to the brother who is born after his older brother died. No verse is needed because the verses of Yibum in the Torah refer only to when the brothers were in the world together, and not to when one brother was born after the first brother died. It is obvious that the younger brother is not included in the Zikah of Yibum.

In contrast, in the case of the Tzarah of an Ervah, the verses of Yibum make no mention of any exclusion of the Tzarah from Yibum. Instead, a different verse ("li'Tzror," which is not in the Parshah of Yibum) teaches that the Tzarah is excluded from Yibum. Since her exclusion is derived from a different source, there are grounds to doubt whether the verse of "li'Tzror" teaches that she is entirely excluded from the Parshah of Yibum (and thus she is excluded from Zikah), or whether it teaches that although she is included in the Parshah of Yibum, she is not able to perform Yibum or Chalitzah (but she nevertheless has Zikah for Yibum).

The same explanation may be suggested according to Rebbi (8b). Rebbi maintains that the verse which teaches that the Tzarah of an Ervah may not do Yibum is in the Parshah of Yibum itself. Since the verse excludes her from the Mitzvah of Yibum, it clearly excludes her from any Zikah as well, and thus, according to Rebbi, no other verse is necessary to exempt the Tzarah of a Tzarah from Yibum.

QUESTION: The Beraisa derives from the verse which teaches the prohibition (Azharah) against marrying "Achos Ishto" (the sister of one's wife) that one is also prohibited from performing Yibum with the Tzarah of an Ervah, and one who performs Yibum with her is punished with Kares. Just as one may not perform Yibum with the Ervah of "Achos Ishto" (and doing so carries the punishment of Kares), so, too, one may not perform Yibum with the Tzarah of "Achos Ishto."

The Gemara says that the Azharah against Yibum with an Ervah or with the Tzarah of an Ervah is derived through a Binyan Av from the Azharah against Yibum with "Achos Ishto" and her Tzarah. This Binyan Av also teaches that the prohibition is punishable with Malkus and with Kares.

How, though, can the Gemara derive a punishment through a Binyan Av? There is a rule that "Ein Onshin Min ha'Din" -- a punishment for a transgression cannot be administered on the basis of an exegetical derivation of a "Kal v'Chomer" (Makos 5b) or "Binyan Av" (see RAN to Nedarim 4b, DH Teisi). (MELO HA'RO'IM)

ANSWER: TOSFOS (DH me'Achos Ishah) points out that the Gemara does not rely on the Binyan Av when it says that the Azharah against Yibum with the other Arayos and their Tzaros is derived from the Azharah of "Achos Ishto," because there are refutations (Pirchos) which prevent deriving some of them from the Binyan Av. Rather, the Beraisa means that there is a Hekesh which links all of the Arayos with each other, as the Gemara later (8a) concludes, and thus all are derived through a Hekesh from "Achos Ishto." A Hekesh is not subject to the restriction of "Ein Onshin Min ha'Din."

The MELO HA'RO'IM challenges this answer. If there is a Hekesh which compares all of the Arayos with each other, then why is the prohibition of the Tzarah of an Ervah limited to the fifteen Arayos mentioned in the Mishnah? The Hekesh should extend the prohibition of Tzarah to the other six, more severe, forms of Arayos! Indeed, the Gemara later (54b) clearly maintains that the Hekesh applies to all of the Arayos. Accordingly, any Halachah which applies to the fifteen Arayos mentioned in the Mishnah should also apply to the six severe Arayos.

Moreover, the Hekesh should teach that Yibum does not apply to a woman who is a Nidah. Since a Nidah is an Ervah (the transgression of living with a Nidah is punishable with Kares), she should be included in the Hekesh (as the Gemara itself says later with regard to other laws). Even if there are reasons to say that a Nidah is more lenient than the other Arayos, "Ein Meshivin Al ha'Hekesh" -- the Hekesh should apply nevertheless. (For example, TOSFOS (2a, DH v'Achos) writes that the Isur of Nidah is less severe than the Arayos mentioned in the Mishnah because the Isur of Nidah is not specific to the husband's brother (the Yavam), but it is a general Isur which applies to every man in the world. In this sense she cannot be called an Ervah (see also TOSFOS HA'ROSH there). RABEINU TAM in SEFER HA'YASHAR (Teshuvos 80:1) writes that the Isur of Nidah is not called an Ervah because it has no permanence; it passes once a certain number of days has gone by and an act of Tevilah has been performed. This explains why the Gemara does not derive a prohibition against performing Yibum with a Nidah through a Binyan Av from Achos Ishto, which is an Ervah. If, however, there is a Hekesh between Nidah and the other Arayos, these "Pirchos" should not be grounds to exclude Nidah from the Hekesh. Why, then, is a woman who was a Nidah at the time her husband died obligated to perform Yibum (when she becomes Tahor)?)

The question from the six severe forms of Arayos may be answered as follows. The Gemara understands from the verse that in a situation of Yibum, a Tzarah of an Ervah is forbidden because the prohibition of "Eshes Ach" remains and prohibits her from marrying her brother-in-law. This is learned from the fact that the Torah teaches the prohibition of "Eshes Ach" specifically in a situation of Yibum. Therefore, in the case of the six severe forms of Arayos -- whom one's brother may never marry (and thus one will never have an obligation to do Yibum with them), there is nothing to which to apply the Hekesh. Just as the Tzaros of the fifteen Arayos are not prohibited when there is no Yibum (for example, when the sister of Shimon's wife was married to an unrelated man, when that man dies Shimon is permitted to marry that man's other wife, the Tzarah of his sister-in-law), so, too, the Tzaros of the six severe forms of Arayos are not prohibited in a normal situation where there is no Yibum.

To answer the question from the case of a Nidah, it may be suggested that the principle of "Ein Meshivin Al ha'Hekesh" means that one may not ask a question (Pircha) on a Hekesh just because one item is more lenient or more severe than the other items included in the Hekesh (even though such a Pircha does remove the item from a Binyan Av or from a Kal v'Chomer). However, if the Pircha involves not merely a leniency or stringency but a logical argument for why one of the items should not be included in the Hekesh, then that logical argument is able to remove the item from the Hekesh and prevent the Halachah from being applied to that item through the Hekesh. (The SEFER KERISUS, in Beis Midos 2:11, makes such a distinction between a Pircha and a logical argument with regard to deriving a Halachah through a Gezeirah Shavah. Although a Hekesh is considered stronger than a Gezeirah Shavah in some matters of Pircha (ibid. 2:14), the SEFER HA'MIKNAH (to Kidushin 15a, DH Mihu) writes that a logical difference can refute a Hekesh as well.) In the case of a Nidah, there is a logical argument which challenges the comparison to the other Arayos, and thus she is removed from the Hekesh. It is not merely a leniency or stringency which exists in the case of a Nidah; there is an essential difference between a Nidah and the other Arayos. This difference is the reason why Kidushin takes effect with a Nidah but not with the other Arayos. Therefore, Nidah is excluded from the Hekesh.

Rabeinu Tam (ibid.) presents a different argument. If the Torah would have intended to include Nidah among the list of women who exempt their Tzaros from Yibum, it would have written the word "li'Tzror" in a verse that discusses Nidah, the most lenient of all of the prohibited women (as she is the only Ervah who becomes permitted after some time passes). The fact that the Torah writes "li'Tzror" in the verse that discusses "Achos Ishto" implies that Nidah is not to be compared to the other Arayos as far as this Halachah is concerned.

(Rabeinu Tam's logic in this matter is not clear. Normally, when there is a Hekesh we do not ask why the Torah reveals a particular law in a particular situation; we compare all of the items in the Hekesh to each other without asking questions. Perhaps Rabeinu Tam means that in this case, another Halachah was already derived through a Hekesh to "Achos Ishto" -- the Halachah that Kidushin cannot take effect with an Ervah (Kidushin 68a). The Torah specifically excludes a Nidah from that Halachah (ibid.). Since one Halachah derived from "Achos Ishto" does not apply to Nidah, it may be assumed that the other Halachos written in the same verse also do not apply to Nidah.)