Genesis 17:16

He who is born in your house, and he who is bought with your money, must be circumcised. My covenant shall be in your flesh for an everlasting covenant.

The uncircumcised male who is not circumcised in the flesh of his foreskin, that soul shall be cut off from his people. He has broken my covenant.”

God said to Abraham, “As for Sarai your wife, you shall not call her name Sarai, but her name shall be Sarah.

Then Abraham fell on his face, and laughed, and said in his heart, “Will a child be born to him who is one hundred years old? Will Sarah, who is ninety years old, give birth?”

Abraham said to God, “Oh that Ishmael might live before you!”

God said, “No, but Sarah, your wife, will bear you a son. You shall call his name Isaac. I will establish my covenant with him for an everlasting covenant for his offspring after him.