Genesis 17:6-11

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.