uncle Laban had two daughters. The name of the older was Leah, and the younger was Rachel. Rachel was beautiful. Jacob was in love with Rachel and said to his uncle that he wanted to marry her. So they had a wedding ceremony.
But when the evening came, his uncle took his first daughter, Leah, and gave her to Jacob. Jacob lay with her without knowing who she was. When the next morning came, Leah was there. So Jacob said to his uncle, “What is this you have done to me? I served you for Rachel, didn't I? Why have you deceived me?” (Gen. 29:25). Laban replied, “It is not our custom here to give the younger daughter in marriage before the older one. Finish this daughter’s bridal week and then we will give you the younger one, in return for another seven years of work” (Gen. 29:26-27). So with the promise of seven years of work, he married the younger daughter as well.
If Jacob was in love with the older daughter, he would have had children only with her. But Jacob loved the younger daughter, so he had four sons first from the older. Furthermore, due to the jealousies of the two, Jacob had two more