Genesis 29:30-34

30Jacob slept with Rachel as well, and indeed, he loved Rachel more than Leah. So he worked for Laban another seven years.

31When the LORD saw that Leah was unloved, He opened her womb; but Rachel was barren. 32And Leah conceived and gave birth to a son, and she named him Reuben,1 for she said, “The LORD has seen my affliction. Surely my husband will love me now.”

33Again she conceived and gave birth to a son, and she said, “Because the LORD has heard that I am unloved, He has given me this son as well.” So she named him Simeon.2

34Once again Leah conceived and gave birth to a son, and she said, “Now at last my husband will become attached to me, because I have borne him three sons.” So he was named Levi.3