Genesis 21:6

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

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

⁶  And Sarah said, God hath made me to laugh, so that all that hear will laugh with me.

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

⁸  And the child grew, and was weaned: and Abraham made a great feast the same day that Isaac was weaned.