Genesis 21:1-4

The Birth of Isaac

21:1 The Lord visited Sarah just as he had said he would and did for Sarah what he had promised. 21:2 So Sarah became pregnant and bore Abraham a son in his old age at the appointed time that God had told him. 21:3 Abraham named his son – whom Sarah bore to him – Isaac. 21:4 When his son Isaac was eight days old, Abraham circumcised him just as God had commanded him to do.