Genesis 17:7-8

17:7 I will confirm my covenant as a perpetual covenant between me and you. It will extend to your descendants after you throughout their generations. I will be your God and the God of your descendants after you. 17:8 I will give the whole land of Canaan – the land where you are now residing – to you and your descendants after you as a permanent possession. I will be their God.”

Genesis 17:24-26

17:24 Now Abraham was 99 years old when he was circumcised; 17:25 his son Ishmael was thirteen years old when he was circumcised. 17:26 Abraham and his son Ishmael were circumcised on the very same day.