Genesis 21:9 WEB

⁷  She said, 'Who would have said to Abraham, that Sarah would nurse children? For I have borne him a son in his old age.'

⁸  The child grew, and was weaned. Abraham made a great feast on the day that Isaac was weaned.

⁹  Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, mocking.

¹⁰  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  The thing was very grievous in Abraham's sight on account of his son.