Genesis 16:1-4

Now Sarai had borne no children for Abram. She had an Egyptian slave girl named Hagar, so Sarai said to Abram, “Please listen. Since YAHWEH has kept me childless, go sleep with my maidservant. Perhaps through her I can build you a family.” Abram listened and did what Sarai asked. Abram had already lived ten years in the land of Canaan when his wife Sarai took her Egyptian slave girl Hagar and gave her to Abram to be his second wife. He slept with Hagar, and she conceived. Once Hagar realized she was pregnant, she belittled Sarai and despised her.