Genesis 21:4-7

4When his son Isaac was eight days old, Abraham circumcised him, as God commanded him.

5Abraham was a hundred years old when his son Isaac was born to him. 6Sarah said, “God has brought me laughter, and everyone who hears about this will laugh with me.”

7And she added, “Who would have said to Abraham that Sarah would nurse children? Yet I have borne him a son in his old age.”