Genesis 21:5 BBE

³  And Abraham gave to his son, to whom Sarah had given birth, the name Isaac.

⁴  And when his son Isaac was eight days old, Abraham made him undergo circumcision, as God had said to him.

⁵  Now Abraham was a hundred years old when the birth of Isaac took place.

⁶  And Sarah said, God has given me cause for laughing, and everyone who has news of it will be laughing with me.

⁷  And she said, Who would have said to Abraham that Sarah would have a child at her breast? for see, I have given him a son now when he is old.