Lech emor lahem shuvu lachem l’ohaleichem (Devorim 5:27)
There is a Talmudic maxim (Yevamos 97b) that ger shenisgayer k’katan shenolad dami – a non-Jew who converts to Judaism is considered for legal purposes to have been newly reborn and is no longer Biblically considered the person he was with the relatives he used to have. In his commentary on Avodah Zara (63b), the Chasam Sofer writes that he has been troubled his entire life at his inability to locate a source for this ruling which the Gemora seems in many places to take for granted.
The Meshech Chochmah suggests that this rule may be derived from our verse. Moshe’s father Amram was one of the greatest men of his generation and was married to Yocheved, his aunt, a marriage which is forbidden to Jewsbut permitted to non-Jews. If one of the leaders was married to such a close relative, it is reasonable to assume that a number of other Jews did likewise and married the various family members which aren’t forbidden to non-Jews.
After the giving of the Torah, Hashem instructed Moshe to tell the people to return to their tents. The Gemora in Moed Katan (7b) understands this as a reference to their wives. Although they were required to abstain from marital relations for 3 days prior to the giving of the Torah in order to receive it in a state of spiritual purity, they were now permitted to resume normal family life. However, after the Torah was given, those Jews who were married to relatives to whom they were now forbidden by the Torah shouldn’t have been allowed to return to their wives, but rather should have been required to divorce them. If Hashem nevertheless told Moshe to permit all of the Jews to return to their wives, it must be that their conversion made them as if they were reborn and no longer related to their wives, thus permitting them to remain married, and from here we may derive the source for the law which the Chasam Sofer sought!
