Bais HaVaad on the Parsha, Parshas Acharei Mos   

Double Take

Excerpted and adapted from a shiur by Dayan Yosef Greenwald

April 28,  2022

You shall not take (lo sikach) a woman in addition to her sister, to make them rivals, to uncover the nakedness of one upon the other in her lifetime.

Vayikra 18:18

Chazal teach that even if such a kidushin were performed, the prohibition of arayos with its chiyuv kareis prevents the kidushin from taking effect. The Sefer Hachinuch (mitzvah 206) writes that still, “lo sikach” teaches that one who does so has violated a prohibition. This chiddush is not accepted by other Rishonim, who hold that since the kidushin is invalid, the ma’aseh is meaningless, so no prohibition has been committed.

The Chinuch appears to contradict a Gemara: If a woman’s husband was thought to have died and she accepted kidushin from another man, no issur is violated if her husband returns before the nisu’in (Yevamos 89). According to the Chinuch, the second man should have transgressed lo sikach, because eishes ish (a married woman) is one of the arayos.

Perhaps the answer is that there is a fundamental difference between other arayos and eishes ish: In the former, the familial relationship precludes the possibility of marriage, so kidushin does not take effect, but a ma’asei kidushin is still halachically meaningful, so an issur was violated. Kidushin of an eishes ish, however, is entirely meaningless, because she is already “taken” and further taking is impossible (see Pnei Yehoshua, Gittin 43).