Leviticus 18:17-19

Complete Jewish Bible

¹⁷ “‘You are not to have sexual relations with both a woman and her daughter, nor are you to have sexual relations with her son’s daughter or her daughter’s daughter; they are close relatives of hers, and it would be shameful. ¹⁸ You are not to take a woman to be a rival with her sister and have sexual relations with her while her sister is still alive. ¹⁹ You are not to approach a woman in order to have sexual relations with her when she is unclean from her time of niddah.