The question is asked how Dina could marry Shimon since they were the children of the same parents. The Rosh on this subject refers to the exchange of fetuses between Leah and Rachel, and says that for this reason they were not siblings of the same mother. However, doesn't halacha say that the woman who BEARS a child is the mother? And according to the Rosh, Rachel would not be considered the real mother of Yosef either! So how would the exchange be appropriate as Leah had wished for? And why did there have to be an exchange, since each Shevet was born with a twin sister?
David Goldman, USA
You seem to assume that the halachic mother is the one who bears the child. However this is not so simple. Rather, it could be that the biological mother is the Halachic mother, not the surrogate.
(1) The proof for this is Chidushei Rebbi Akiva Eiger to Shulchan Arukh YD 87 to Shach #14. The discussion starts from Gemara Chulin 113b which cites Shemos 23:19 "You shall not cook a goat in the milk of its mother." The Gemara explains that "the milk of its mother" comes to exclude the milk of a slaughtered animal (i.e. there is no d'Oraisa prohibition against cooking meat in the milk of a slaughtered animal). Rashi explains that since the Torah says "its mother", this implies that the prohibition only applies if the animal is capable of being a mother, not if it has already been slaughtered.
(2) On the basis of the above, Rebbi Akiva Eiger now raises the question what would be the Din if one cooked meat in the milk of a Tereifah animal (i.e. an animal of a Kosher species, which possesses one of the Tereifos, e.g. a hole in the lung)? Since the Halachah is that a Tereifah animal is not capable of giving birth (see Chulin 57b), does this mean that a Tereifah animal is not capable of being a mother and therefore the milk cooked in its meat would be permitted mid'Oraisa?
(3) Rebbi Akiva Eiger solves this problem from Sanhedrin 69a Rashi DH Ela, that if 3 months have passed since a boy produced pubic hairs, the Din of Ben Sorer u'Moreh (the rebellious son) no longer applies to him, because by this time he is no longer a "son" but rather is capable of being a father, since 3 months ago he was capable of making a woman pregnant, and after 3 months have passed one can already see that the woman is expecting. This proves that a person is defined as a father as soon as the fetus that he has fathered is recognizable.
(4) Rebbi Akiva Eiger asserts that just like a man is considered a father once the fetus can be discerned, similarly a woman is considered a mother at that stage. Therefore a Tereifah can also be a mother, because the Shach YD 57:45 states that a Tereifah is capable of becoming pregnant even though it is not capable later of actually giving birth.
(5) The above is Rebbi Akiva Eiger's proof that motherhood depends on conception, not on birth. (This is cited by the Beis ha'Otzar, by Rabbi Yosef Engel, entry on Fatherhood, vol. 1, p.29 at top.)
(6) However the Beis ha'Otzar also cites another source which suggests the opposite. This is from Megilah 13a which states that Esther did not have either a father or a mother, because when her mother became pregnant her father died (Rashi explains that therefore there was no father at the time that fatherhood starts - i.e. when the fetus is recognizable) and her mother died in childbirth, so there was no mother at the time that motherhood starts (i.e. at childbirth). The Beis ha'Otzar cites the Maharal of Prague who proves from here that motherhood depends on giving birth.
(7) I would like to try the following Pshat to answer your question. We now have two definitions of motherhood (1) biological (2) surrogate. Regarding the prohibition of a Ben No'ach marrying his sister, this only applies if she is his sister in both respects. Therefore Shimon was permitted to marry Dinah because he was conceived by Leah while Dinah was conceived by Rachel. In contrast, it is enough to have either (1) or (2) for Rachel to be considered the mother of Yosef, to be considered now as possessing two Shevatim from her sons. Yosef and Dinah both had two mothers, but since Rachel delivered Yosef, she was no longer considered as worse than the Shefachos, since she had now contributed two Shevatim to Bnei Yisrael.
[It should be pointed out that with regards to the contemporary Halachic question concerning who is the mother - the biological or the surrogate - one must be wary of citing proofs similar to the above, because we have a rule "Ein Lemeidim Halachos Min ha'Agados" - one cannot derive Halachos from Agados].
KOL TUV
Dovid Bloom
Dear R. Dovid Bloom: This is very interesting, and shows the depths to which a kashe in Tanach can go.
The reference to the Rosh was apparently through the Tur Aruch, his son, on the posuk about Shaul ben Haknaanis. I understand there is also a shita that says that Bnai Noach are allowed to married sisters. But can we describe the avos and shvatim as Bnai Noach? Someone also suggested the idea that geyrus was involved with the avos and shvatim, so technically speaking Shimon and Dina were not siblings. Furthermore, there are apparently contradictory midrashim, indicating that Dina was married to others, and not Shimon.
I just don't understand something. How can it be said that Yosef and Dina had TWO mothers? Is that a technical halachic category?
(1) Can we describe the avos and the shvatim as Bnai Noach?
Well, an awful lot of ink has been spilt on this subject but I will just mention one source. The Gemara in Chulin 91a relates that when Yosef ate together with his brothers in Egypt, he showed them the way the neck of the animal had been slaughtered so that they could confirm that the slaughtering had been done properly. Rashi DH u'Pora explains that even though the Torah had not yet been given, nevertheless the sons of Yaakov observed the Mitzvos because they possessed this tradition from their forefathers. I understand from Rashi that the way the Shevatim kept the Mitzvos is different than the way Avraham Avinu kept the Mitzvos. The Gemara in Yoma 28b states that Avraham observed the entire Torah. This implies that he accepted it upon himself as an obligation. In contrast, the Shevatim observed it as a family tradition. (See additional explanations in Tosfos Chulin 91a DH k'Man and Rashba, Ritva and Chidushei ha'Ran there.)
(2) I do not understand the explanation about the Gerus on Shimon and Dinah because this implies that after they were born, Shimon and Dinah underwent Gerus before they got married. Since they were born to Yaakov, who observed the Torah, there does seem to be any source to say that this is what happened, nor any logical reason that they would have to do this.
(3) I agree that my idea about dual motherhood is a novel one and I admit that I got onto it via the contemporary question of surrogate motherhood. Firstly, I must say that my intention here is by no means to enter a Halachic discussion but I will add that Rav Elyashiv is opposed to any fertility treatments that involve anyone other than the husband and wife. However since some people do these things these questions do sometimes arrive in the Batei Dinim.
Just to recap very briefly on the sources. The Gemara in Megilah states that Esther had no father or mother because when her mother became pregnant her father died (so she had no father at the time that fatherhood starts) and her mother died when she delivered her, which is the time when motherhood starts. However, Rashi in Sanhedrin 69a DH Ella writes that fatherhood commences at the time when one can see that the mother is pregnant and Rebbi Akiva Eiger writes that if so, motherhood also starts at the latter time. To reconcile this contradiction I suggested that in fact to possess entire motherhood she has both to conceive and bear the child, but if she does one of the latter two, she is considered a partial mother.
I have a source for this from Bereishis 46:22 which states "These are the sons of Rachel that were born ("Yulad") to Yaakov". Why does it not say "that she bore (Yoldo")"? The Meshech Chochmah answers on the basis of the Targum Yonasan Bereishis 30:21 that we mentioned last time, that the embryos of Yosef and Dinah were switched around in the wombs. The Gemara in Nidah end 31a states that "Yoldo" refers to the conception. Since Rachel did not conceive Yosef, the Torah could not say "Yoldo". The Torah is telling us that the motherhood of Rachel for Yosef was only partial.
Chodesh Tov
Dovid Bloom