Genesis 21
9 Ref Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, mocking.
10 Ref Therefore she said to Abraham, "Cast out this handmaid and her son! For the son of this handmaid will not be heir with my son, even with Isaac."
11 Ref The thing was very grievous in Abraham's sight on account of his son.
12 Ref God said to Abraham, "Don't let it be grievous in your sight because of the boy, and because of your handmaid. In all that Sarah says to you, listen to her voice. For from Isaac will your seed be called.
13 Ref Also of the son of the handmaid will I make a nation, because he is your seed."