Imamat 18:16

18:16 You must not have sexual intercourse with your brother’s wife; she is your brother’s nakedness. ¹ 

Imamat 18:18

18:18 You must not take a woman in marriage and then marry her sister as a rival wife ²  while she is still alive, ³  to have sexual intercourse with her.

[18:16]  ¹ sn Regarding the last clause, see the notes on vv. 7 and 10 above.

[18:18]  ² tn Or “as a concubine”; Heb “And a woman to her sister you shall not take to be a second wife [or “to be a concubine”].” According to HALOT 1059 s.v. III צרר, the infinitive “to be a second wife” (לִצְרֹר, litsror) is a denominative verb from II צָרָה A (“concubine; second wife”), which, in turn, derives from II צר “to treat with hostility” (cf. J. E. Hartley, Leviticus [WBC], 283, and B. A. Levine, Leviticus [JPSTC], 122).

[18:18]  ³ tn Heb “on her in her life.”