(Laban) took his two handmaids, and gave them to his two daughters. Were they his handmaids? Were they not his daughters? But according to the law of the land the daughters of a man by his concubines are called handmaids, as it is said, "And Laban gave to Rachel his daughter Bilhah his handmaid to be her handmaid" (Gen. 29:29).
Rabbi Levi said: The Holy One, blessed be He, saw the sorrow of Leah, and He gave her power to conceive, (bringing) consolation to her soul; and she bare a male child, goodly in appearance, and wise; and she said: See ye a son which the Holy One, blessed be He, has given me, as it is said, "And Leah conceived, and bare a son, and she called his name Reuben; for she said, Because the Lord hath looked upon my affliction" (Gen. 29:32). Therefore he called his name Reuben.