Genesis 16:2-4

So Sarai said to Abram, “See now, the LORD has restrained me from bearing children. Please, go in to my maid; perhaps I shall obtain children by her.” And Abram heeded the voice of Sarai. Then Sarai, Abram’s wife, took Hagar her maid, the Egyptian, and gave her to her husband Abram to be his wife, after Abram had dwelt ten years in the land of Canaan. So he went in to Hagar, and she conceived. And when she saw that she had conceived, her mistress became despised in her eyes.