Leviticus 18:17-19

The Voice

¹⁷ You are not to have sexual relations with a woman and her daughter, her son’s daughter, or her daughter’s daughter; they are blood relations. It would be a disgusting act. ¹⁸ As long as your wife is living, do not marry her sister or have sexual relations with her. This would make them rivals.

¹⁹ You are not to have sexual relations with a woman while she is in her menstrual impurity.