Genesis 16:3-6

After Abram had lived in the land of Canaan ten years, Abram’s wife Sarai took Hagar the Egyptian [maid], and gave her to her husband Abram to be his [secondary] wife. He went in to [the bed of] Hagar, and she conceived; and when she realized that she had conceived, she looked with contempt on her mistress [regarding Sarai as insignificant because of her infertility]. Then Sarai said to Abram, “May [the responsibility for] the wrong done to me [by the arrogant behavior of Hagar] be upon you. I gave my maid into your arms, and when she realized that she had conceived, I was despised and looked on with disrespect. May the LORD judge [who has done right] between you and me.” But Abram said to Sarai, “Look, your maid is entirely in your hands and subject to your authority; do as you please with her.” So Sarai treated her harshly and humiliated her, and Hagar fled from her.