The patriarchs – Abraham, Isaac, and Jacob – observed the Torah’s laws before they were formally given on Mount Sinai. Nonetheless, we have seen that Jacob’s sons married their sisters. The reason for this was because society was so morally depraved in the patriarchs’ times that there were simply no suitable choices for marriage partners outside the family circle. In those early days, it was crucial to preserve the spiritual and moral integrity of the family that was being groomed to become the Jewish people. Therefore, in order to ensure that their children not inherit negative traits from unworthy mothers or absorb negative attitudes while being raised by these women, Abraham’s male descendants were forced not to honor these prohibitions, which in any case would only become legally binding with the Giving of the Torah on Mount Sinai.
We learn from this how much care we should take to ensure that our children’s upbringing and environment support and encourage their absorption of the Torah’s teachings and values.1
According to the Torah, Jacob’s only daughter was named Dinah. How could all 12 of Jacob’s sons marry a sister when they only had one sister? The Torah also names some of the wives of Jacob’s sons, including Joseph’s Egyptian wife named Osnat and other wives of Jacob’s sons who were clearly not their sister. I understand the very valid lesson of how important a child’s environment is in becoming a mensch. I hope you will please explain how Jacob’s sons all married sisters when the Torah says they only had one sister and that Joseph married an Eygptian woman while other brothers also married women who were not their sister. Thanks.
Good question!
1) The Talmud identifies Osnat as a daughter of Dinah and Chamor (Baba Batra 15b, but see Rashi to Genesis 46:10 where Saul the son of the Canaanite was the child of that union).
But, either way, Joseph would have been the exception, as he was sold before he was married.
2) According to this view, Dinah was unique in that she was not born with a twin. That is why she was singled out. Alternatively, she is singled out because she was not married at this point. The Torah counted only couples.
3) Rashi to Genesis 46:26 writes: " According to the one who says that twin sisters were born with [each of the progenitors of] the tribes (37: 35), we must say that they died before their descent to Egypt, for they were not counted here."
Besides Osnat, no other wives are named.
Thanks for the clarifications and their sources. Many thanks for all the outreach and learning resources provided by Chabad worldwide.