Genesis 30:14-16

14And Reuben went out in the days of wheat-harvest, and found mandrakes in the fields; and he brought them to his mother Leah. And Rachel said to Leah, Give me, I pray thee, of thy son's mandrakes.

15And she said to her, Is it [too] little that thou hast taken my husband, that thou wilt take my son's mandrakes also? And Rachel said, Therefore he shall lie with thee to-night for thy son's mandrakes.

16And when Jacob came from the fields in the evening, Leah went out to meet him, and said, Thou must come in to me, for indeed I have hired thee with my son's mandrakes. And he lay with her that night.