Genesis 17:1-15

Now when Abram was ninety-nine years old, the LORD appeared to Abram and said to him, “I am God Almighty; Walk before Me, and be blameless. I will establish My covenant between Me and you, And I will multiply you exceedingly.” Abram fell on his face, and God talked with him, saying, “As for Me, behold, My covenant is with you, And you will be the father of a multitude of nations. No longer shall your name be called Abram, But your name shall be Abraham; For I have made you the father of a multitude of nations. I will make you exceedingly fruitful, and I will make nations of you, and kings will come forth from you. I will establish My covenant between Me and you and your descendants after you throughout their generations for an everlasting covenant, to be God to you and to your descendants after you. I will give to you and to your descendants after you, the land of your sojournings, all the land of Canaan, for an everlasting possession; and I will be their God.” God said further to Abraham, “Now as for you, you shall keep My covenant, you and your descendants after you throughout their generations. This is My covenant, which you shall keep, between Me and you and your descendants after you: every male among you shall be circumcised. And you shall be circumcised in the flesh of your foreskin, and it shall be the sign of the covenant between Me and you. And every male among you who is eight days old shall be circumcised throughout your generations, a servant who is born in the house or who is bought with money from any foreigner, who is not of your descendants. A servant who is born in your house or who is bought with your money shall surely be circumcised; thus shall My covenant be in your flesh for an everlasting covenant. But an uncircumcised male who is not circumcised in the flesh of his foreskin, that person shall be cut off from his people; he has broken My covenant.” Then God said to Abraham, “As for Sarai your wife, you shall not call her name Sarai, but Sarah shall be her name.