Genesis 17:13-15

English Standard Version Anglicised

¹³ both he who is born in your house and he who is bought with your money, shall surely be circumcised. So shall my covenant be in your flesh an everlasting covenant. ¹⁴ Any uncircumcised male who is not circumcised in the flesh of his foreskin shall be cut off from his people; he has broken my covenant.”

Isaac's Birth Promised

¹⁵ And God said to Abraham, “As for Sarai your wife, you shall not call her name Sarai, but Sarah^[a] shall be her name.