Sanhedrin Daf 75 סַנהֶדרִין דַף 75

Rav related that a certain man became obsessed with a woman until he became dangerously ill. Doctors said he has no cure but to have relations with her, but the Sages ruled: ימות ואל תבעל לו – he should die rather than have relations with her. The doctors suggested she stand before him unclothed, but the Sages again ruled it is better that he should die. Finally, the doctors suggested she merely speak with him from behind a barrier, but they ruled: ימות ולא תספר עמו מאחורי הגדר – he should die rather than let her speak with him from behind a barrier. Amoraim debate if the woman was married or unmarried. If she was married, it is understandable why he should die rather than interact with her in these ways, which are אביזרייהו – subsidiaries of עריות. But if she was unmarried, why did they not allow these activities? Rav Pappa says: משום פגם משפחה – because of the disgrace to her family. Rav Acha brei d’Rav Ikka says: כדי שלא יהו בנות ישראל פרוצות בעריות – so that the daughters of Yisroel should not be immodest regarding עריות (i.e., so women would not attract men to themselves this way). [He did not marry her, because since the destruction of the Beis Hamikdash, the pleasure of relations was taken from married people and given to sinners.]

The ninth Perek begins: ואלו הן הנשרפין – these are the ones who are burned: הבא על אשה ובתה – one who has relations with a mother and her daughter, ובת כהן שזנתה – and a Kohen’s daughter who commits adultery. Included in "אשה ובתה" (which is written explicitly) are one’s daughter, his granddaughter (from either his son or daughter), his wife’s daughter or granddaughter (from her son or daughter), his mother-in-law, and the mother of his mother-in-law or father-in-law. The Mishnah does not say “one who has relations with אשה שנשא בתה – a woman whose daughter he married” (i.e., his mother-in-law), but with “a woman and her daughter,” implying both women are prohibited (i.e., their שריפה punishment is taught explicitly). Since the explicit passuk of שריפה is written regarding חמותו – his mother-in-law, this must refer to the mother of his mother-in-law and “her daughter,” i.e., his mother-in-law, saying that both are included in the passuk of שריפה. This fits according to Abaye, who holds that Rebbe Akiva does include אם חמותו in the passuk, but according to Rava, no Tanna holds this way!? Therefore, Rava must read the Mishnah as “one who has relations with אשה שנשא בתה – a woman whose daughter he married,” i.e., his mother-in-law.

A Baraisa derives from a gezeirah shavah (זמה זמה) that שריפה applies to a wife’s daughter and granddaughter. The Baraisa additionally derives from the gezeirah shavah to make זכרים כנקיבות – males like females, and Abaye ultimately explains: לעשות שאר הבא ממנו – to make the relatives which come from him (the husband) כשאר הבא ממנה – like the relatives which come from her (the wife); just as his wife’s daughter and granddaughters are punished with שריפה, the same applies to his own daughter and granddaughters. Finally, the Baraisa derives from the gezeirah shavah to make "למטה כלמעלה" – what is below like what is above. Abaye explains the phrase reversed (deriving to make “above” like “below”), to apply שריפה to שלשה דורות למעלה – three generations above (i.e., his wife’s grandmothers) כשלשה דורות למטה – like three generations below (his wife’s granddaughters) to receive שריפה. Rav Ashi says, without reversing the phrase, that "למטה" means למטה באיסור – “below” in the prohibition’s severity, and teaches that a grandmother-in-law, who is less related than a mother-in-law, incurs שריפה like she does.