Leviticus 18:15

15 Thou shalt not uncover the nakedness of thy daughter-in-law, for she is thy son's wife, thou shalt not uncover her nakedness.

Leviticus 18:15 Meaning and Commentary

Leviticus 18:15

Thou shall not uncover the nakedness of thy daughter in law,
&c.] Shall not he with her in his son's lifetime, or marry her after his death: she [is] that son's wife;
and so one flesh with him, and who is of the same flesh and blood with his father, and therefore the nearness of the relation forbids such incestuous copulation or marriage: thou shall not uncover her nakedness;
or have carnal knowledge of her, whether in the life or after the death of his son, even then marriage with her is not lawful.

Leviticus 18:15 In-Context

13 Thou shalt not uncover the nakedness of thy mother's sister, for she is near akin to thy mother.
14 Thou shalt not uncover the nakedness of thy father's brother, and thou shalt not go in to his wife; for she is thy relation.
15 Thou shalt not uncover the nakedness of thy daughter-in-law, for she is thy son's wife, thou shalt not uncover her nakedness.
16 Thou shalt not uncover the nakedness of thy brother's wife: it is thy brother's nakedness.
17 The 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.

The Brenton translation of the Septuagint is in the public domain.