Genesis 19:34
19:34 So in the morning the older daughter said to the younger, “Since I had sexual relations with my father last night, let’s make him drunk again tonight. Then you go and have sexual relations with him so we can preserve our family line through our father.”
Genesis 30:15
30:15 But Leah replied, “Wasn’t it enough that you’ve taken away my husband? Would you take away my son’s mandrakes too?” “All right,” Rachel said, “he may sleep with you tonight in exchange for your son’s mandrakes.”