15 But she said to her, "Is it a small matter that you have taken away my husband? Would you take away my son's mandrakes also?" Rachel said, "Then he may lie with you tonight in exchange for your son's mandrakes." 16 When Jacob came from the field in the evening, Leah went out to meet him and said, "You must come in to me, for I have hired you with my son's mandrakes." So he lay with her that night.
Matthew Henry's Commentary on Genesis 30:15-16
Commentary on Genesis 30:14-24
(Read Genesis 30:14-24)
The desire, good in itself, but often too great and irregular, of being the mother of the promised Seed, with the honour of having many children, and the reproach of being barren, were causes of this unbecoming contest between the sisters. The truth appears to be, that they were influenced by the promises of God to Abraham; whose posterity were promised the richest blessings, and from whom the Messiah was to descend.