Leviticus 15:19

Female Bodily Discharges

15:19 “‘When a woman has a discharge and her discharge is blood from her body, she is to be in her menstruation seven days, and anyone who touches her will be unclean until evening.

Leviticus 18:11

18:11 You must not have sexual intercourse with the daughter of your father’s wife born of your father; she is your sister. You must not have intercourse with her.