Leviticus 18:17-20

17Do not have sex with both a woman and her daughter. Do not have sex with her son's daughter or with her daughter's daughter. They are her near relatives. It would be an evil thing to do.

18Do not marry your wife's sister as a second wife. If your wife is still alive, do not have sex with her sister.

19Do not have sex with a woman at the time when she bleeds each month. She is unclean during that time.

20Do not have sex with the wife of another man. You would become unclean.