Genesis 21:1-6 KJV

1 And the LORD visited Sarah as he had said , and the LORD did unto Sarah as he had spoken .
2 For Sarah conceived , and bare 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 that was born unto him, whom Sarah bare to him, Isaac.
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.