Genesis 16:2-4 RSV

2 and Sar'ai said to Abram, "Behold now, the LORD has prevented me from bearing children; go in to my maid; it may be that I shall obtain children by her." And Abram hearkened to the voice of Sar'ai.
3 So, after Abram had dwelt ten years in the land of Canaan, Sar'ai, Abram's wife, took Hagar the Egyptian, her maid, and gave her to Abram her husband as a wife.
4 And he went in to Hagar, and she conceived; and when she saw that she had conceived, she looked with contempt on her mistress.