Exodus 21:9-11

Amplified Bible

⁹ If her master chooses her [as a wife] for his son, he shall act toward her as if she were legally his daughter. ¹⁰ If her master marries another wife, he may not reduce her food, her clothing, or her privilege as a wife. ¹¹ If he does not do these three things for her, then shall she leave free, without payment of money.