Leviticus 18:18
King James Version
Neither shalt thou take a wife to her sister, to vex her, to uncover her nakedness, beside the other in her life time.
Leviticus 18:18 in context
Thou shalt not uncover the nakedness of thy brother’s wife: it is thy brother’s nakedness.
Thou 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.
Neither shalt thou take a wife to her sister, to vex her, to uncover her nakedness, beside the other in her life time.
Also thou shalt not approach unto a woman to uncover her nakedness, as long as she is put apart for her uncleanness.
Moreover thou shalt not lie carnally with thy neighbour’s wife, to defile thyself with her.