Leviticus 18:9-11

9The nakedness of thy sister, the daughter of thy father, or daughter of thy mother, whether born at home, or born abroad, even their nakedness thou shalt not uncover. 10The nakedness of thy son’s daughter, or of thy daughter’s daughter, even their nakedness thou shalt not uncover: for theirs is thy own nakedness. 11The nakedness of thy father’s wife’s daughter, begotten by thy father, she is thy sister, thou shalt not uncover her nakedness.