Leviticus 18:17-19

Names of God Bible

¹⁷ Never have sexual intercourse with a woman and her daughter or a woman and her granddaughter. They are related. Doing this is perverted. ¹⁸ While your wife is living, never marry her sister as a rival wife and have sexual intercourse with her.

¹⁹ “Never have sexual intercourse with a woman while she is unclean during her monthly period.