Genesis 29:27-31

“But wait until the bridal week is over; then we’ll give you Rachel, too—provided you promise to work another seven years for me.” So Jacob agreed to work seven more years. A week after Jacob had married Leah, Laban gave him Rachel, too. (Laban gave Rachel a servant, Bilhah, to be her maid.) So Jacob slept with Rachel, too, and he loved her much more than Leah. He then stayed and worked for Laban the additional seven years. When the LORD saw that Leah was unloved, he enabled her to have children, but Rachel could not conceive.