Imamat 18:8

18:8 You must not have sexual intercourse with your father’s wife; she is your father’s nakedness. ¹ 

Imamat 18:15

18:15 You must not have sexual intercourse with your daughter-in-law; she is your son’s wife. You must not have intercourse with her.

Imamat 18:20

18:20 You must not have sexual intercourse ²  with the wife of your fellow citizen to become unclean with her.

[18:8]  ¹ tn Heb “the nakedness of your father she is.” See the note on v. 7 above. This law refers to another wife of the man’s father, who is not that man’s mother. The laws in the Pentateuch sometimes assume the possibility that a man may have more than one wife (cf., e.g., Deut 21:15-17).

[18:20]  ² tn Heb “And to the wife of your fellow citizen you shall not give your layer for seed.” The meaning of “your layer” (שְׁכָבְתְּךָ, shÿkhavtÿkha) is uncertain (see B. A. Levine, Leviticus [JPSTC], 122, “you shall not place your layer of semen”; but cf. also J. E. Hartley, Leviticus [WBC], 283, and the literature cited there for the rendering, “you shall not give your penis for seed”).