Genesis 21:6-10

Sarah said, “God has made laughter for me; everyone who hears will laugh with me.” And she said, “Who would have said to Abraham that Sarah would nurse children? Yet I have borne him a son in his old age.” The child grew and was weaned, and Abraham made a great feast on the day that Isaac was weaned. Now Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, mocking. Therefore she said to Abraham, “Drive out this maid and her son, for the son of this maid shall not be an heir with my son Isaac.”