Genesis 21:1-7 

Isaac Is Born

21 And the Lord visited Sarah as He had said, and the Lord did for Sarah as He had spoken. ² For Sarah conceived and bore Abraham a son in his old age, at the set time of which God had spoken to him. ³ And Abraham called the name of his son who was born to him—whom Sarah bore to him—Isaac. ⁴ Then Abraham circumcised his son Isaac when he was eight days old, as God had commanded him. ⁵ Now Abraham was one hundred years old when his son Isaac was born to him. ⁶ And Sarah said, “God has made me laugh, and all who hear will laugh with me.” ⁷ She also said, “Who would have said to Abraham that Sarah would nurse children? For I have borne him a son in his old age.”