Leviticus 18:15-18

¹⁵Thou shalt not uncover the nakedness of thy daughter-in-law, for 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.

¹⁷The nakedness of a woman and her daughter shalt thou not uncover; her son’s daughter, and her daughter’s daughter, shalt thou not take, to uncover their nakedness, for they are thy kinswomen: it is impiety.

¹⁸Thou shalt not take a wife in addition to her sister, as a rival, to uncover her nakedness in opposition to her, while she is yet living.