Leviticus 18:18-20

EasyEnglish Bible

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

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

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