Genesis 21:6

Abraham called his son who was born to him, whom Sarah bore to him, Isaac.

Abraham circumcised his son, Isaac, when he was eight days old, as God had commanded him.

Abraham was one hundred years old when his son, Isaac, was born to him.

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

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

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