Leviticus 18:17

15Thou shalt not uncover the nakedness of thy daughter in law: she is thy son’s wife; thou shalt not uncover her nakedness.

16Thou shalt not uncover the nakedness of thy brother’s wife: it is thy brother’s nakedness.

17Thou shalt not uncover the nakedness of a woman and her daughter, neither shalt thou take her son’s daughter, or her daughter’s daughter, to uncover her nakedness; for they are her near kinswomen: it is wickedness.

18Neither shalt thou take a wife to her sister, to vex her, to uncover her nakedness, beside the other in her life time.

19Also thou shalt not approach unto a woman to uncover her nakedness, as long as she is put apart for her uncleanness.