Leviticus 18:8
18:8 You must not have sexual intercourse with your father’s wife; she is your father’s nakedness.
Leviticus 18:16
18:16 You must not have sexual intercourse with your brother’s wife; she is your brother’s nakedness.
Leviticus 18:20
18:20 You must not have sexual intercourse with the wife of your fellow citizen to become unclean with her.