Halakhah zu Bereschit 46:10

However, the Tur (Peirush Tur Ha’aroch on Bereishit 46:10) explains this midrash in a manner that seemingly indicates the exact opposite, that the ovum donor is the halachic mother in a case of surrogate motherhood. In analyzing the midrash (quoted by Rashi on Bereishit 46:10) that Shimon married his sister, Dinah, the Tur wonders why their union did not constitute incest. After all, Shimon and Dinah were both children of Leah, and marrying a maternal sister was prohibited even before the giving of the Torah. The Tur answers that, as quoted above from Targum Yonatan, Dinah began in Rachel’s womb. Even after she was switched to Leah’s womb, the Halachah still considered her to be Rachel’s daughter, so she and Shimon thus had different mothers. Before the Torah was given, one was allowed to marry a paternal half-sister.¹¹Even nowadays, Noachide Law (Halachah pertaining to non-Jews) permits marrying a paternal half-sister, while a Jew may not marry any half-sister; see Vayikra 18:9, Rambam (Hilchot Melachim 9:5), and Rashi (Bereishit 20:12). Therefore, Leah’s son, Shimon, did not violate the Halachah when he married Rachel’s daughter, Dinah. We thus see that according to the Tur, the Halachah defines motherhood by the woman whose egg forms the fetus, even if another woman gives birth to the baby. Of course, Aggadic passages usually cannot serve as definitive halachic proofs.¹²See Yerushalmi (Pe’ah 2:4), Encyclopedia Talmudit (1:62), Teshuvot Yabia Omer (vol. 8, Even Ha’ezer 21:2), and Nishmat Avraham (3:17). Nevertheless, the Tur’s words merit serious halachic consideration, especially because he is explaining how to understand the story from a halachic perspective.

An argument based upon an aggadic source establishing the opposite conclusion was first advanced by R. Menasheh Grossberg, Sha'arei Torah, Sha'ar Menasheh, XV (5684), no. 3. The Gemara, Berakhot 60a, declares that Dinah was born a female as a result of Leah's prayers during her pregnancy. Knowing that Jacob would become the father of a total of twelve sons and not wishing her sister Rachel to bear their husband fewer sons than the maidservants, Bilhah and Zilpah, Leah prayed that her already conceived fetus be born a female. It is clear from the parallel narrative recorded in the Palestinian Talmud, Berakhot 9:3, that the phenomenon described by the Sages involved an in utero sex change. However, Targum Yonatan, Genesis 30:21, states that what transpired was not a sex change in Leah's fetus but a physical exchange of the fetus from the womb of Leah to the womb of Rachel and vice versa, i.e., Dinah was conceived by Rachel but transferred to the womb of Leah while Joseph was conceived by Leah and transferred to the womb of Rachel.¹See also R. Chaim Yosef David Azulai, Devash le-Pi, ma‘arekhet ayin, s.v. ayin ha-ra. This view, attributed to a midrashic source, is also cited by Ba‘alei ha-Tosafot, Moshav Zekenim (London, 5719), Genesis 46:10 and in Peirush ha-Tur he-Arukh, Genesis 30:21. See also Meshekh Ḥokhmah, Parshat Va-Yeḥi, s.v. bnei Raḥel. Maharsha, Niddah 31a, asserts that this is also the correct interpretation of the narrative recorded in Berakhot 60a. The liturgical poem "Even Hug," attributed to R. Eleazar ha-Kalir, which is included in the repetition of the amidah of Shaḥarit on the first day of Rosh ha-Shanah contains a passage predicated upon the identical premise: "Zakhar lah yosher araḥot, ubar le-hamir be-veten aḥot; ḥushavah ke-ha-yom zikhrah le-he'aḥot, siluf Dinah bi-Yehosef le-hanḥot—God remembered her righteous ways and exchanged the fetus in the womb of her sister; on this day was considered her remembrance in reward for her sisterly affection²Or perhaps, “on this day was considered her remembrance to make her equal to her sister.” and the exchange of Dinah for Joseph was effected." Kotnot Or cites Targum Yonatan in resolving a question posed by R. Elijah Mizrahi in the latter's commentary on Genesis 46:10 with regard to the tradition which teaches that Simeon took Dinah as a wife. R. Elijah Mizrahi is troubled by the fact that even a Noachide is forbidden to marry his sister. Kotnot Or points out that only a maternal sister is forbidden to a Noachide; a half-sister who is a paternal sibling is permitted to a Noachide. Kotnot Or observes that, according to Targum Yonatan, Dinah was really the daughter of Rachel and hence not a maternal sister of Simeon. The implication of Kotnot Or's thesis is that the maternal relationship is established by conception rather than birth.³See also R. Yonatan ha-Levi Eibeschutz, Ha-Be’er, VIII (5693), no. 3. A position identical to that of Kotnot Or is espoused by Moshav Zekenim, Genesis 46:10 and tentatively advanced by Peirush ha-Tur he-Arukh, Genesis 46:10.