Genesis 21:8-14 NRSV
The child grew, and was weaned; and Abraham made a great feast on the day that Isaac was weaned. But Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, playing with her son Isaac. So she said to Abraham, “Cast out this slave woman with her son; for the son of this slave woman shall not inherit along with my son Isaac.” The matter was very distressing to Abraham on account of his son. But God said to Abraham, “Do not be distressed because of the boy and because of your slave woman; whatever Sarah says to you, do as she tells you, for it is through Isaac that offspring shall be named for you. As for the son of the slave woman, I will make a nation of him also, because he is your offspring.” So Abraham rose early in the morning, and took bread and a skin of water, and gave it to Hagar, putting it on her shoulder, along with the child, and sent her away. And she departed, and wandered about in the wilderness of Beer-sheba.
NRSV: New Revised Standard Version