Genesis 17:22

And as for Ishmael, I have heard thee: Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly; twelve princes shall he beget, and I will make him a great nation.

But my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year.

And Abraham took Ishmael his son, and all that were born in his house, and all that were bought with his money, every male among the men of Abraham's house; and circumcised the flesh of their foreskin in the selfsame day, as God had said unto him.

And Abraham [was] ninety years old and nine, when he was circumcised in the flesh of his foreskin.