Genesis 21:5 ASV

³  And Abraham called the name of his son that was born unto him, whom Sarah bare to him, Isaac.

⁴  And Abraham circumcised his son Isaac when he was eight days old, as God had commanded him.

⁵  And Abraham was a hundred years old, when his son Isaac was born unto him.

⁶  And Sarah said, God hath made me to laugh. Every one that heareth will laugh with me.

⁷  And she said, Who would have said unto Abraham, that Sarah should give children suck? For I have borne him a son in his old age.