Genesis 17:19-23

But God said, “No, but your wife Sarah will bear you a son, and you shall name him Isaac; and I will establish My covenant with him as an everlasting covenant for his descendants after him.

As for Ishmael, I have heard you; behold, I will bless him, and make him fruitful and multiply him exceedingly. He shall father twelve princes, and I will make him into a great nation.

But I will establish My covenant with Isaac, whom Sarah will bear to you at this season next year.”

When He finished talking with him, God went up from Abraham.

Then Abraham took his son Ishmael, and all the slaves who were born in his house and all who were bought with his money, every male among the men of Abraham’s household, and circumcised the flesh of their foreskin on this very same day, as God had said to him.