Leviticus 18:11-13

¹¹The nakedness of thy father's wife's daughter, begotten of thy father: she is thy sister: thou shalt not uncover her nakedness.

¹²The nakedness of thy father's sister shalt thou not uncover: she is thy father's near relation.

¹³The nakedness of thy mother's sister shalt thou not uncover; for she is thy mother's near relation.