2,033. A Daughter

Hilchos Issurei Biah 2:6

If a man has promiscuous relations with a woman and conceives a daughter with her, that daughter is a prohibited relation to him; this is a Biblical prohibition even though the Torah does not explicitly state the prohibition of a daughter. Since the Torah prohibited relations with the daughter of one’s daughter, it wasn’t necessary to mention one’s daughter; this is not a rabbinic prohibition. Therefore, one who has relations with a daughter born to his wife is liable for two offerings: one for relations with a daughter and one for having relations with both a woman and her daughter.

Hilchos Issurei Biah 2:7

When a man betroths a woman, her six close relatives become prohibited to him as perpetual forbidden relationships. This is so regardless of whether he completes the marriage or divorces the woman from betrothal, both in her lifetime and after her death. The six women are her mother, her mother’s mother, her father’s mother, her daughter, her daughter’s daughter and her son's daughter. If a man has relations with one of these women during his wife’s lifetime, both parties are subject to execution by burning.