Genesis 17:1-27

When Abram was 99 years old, the LORD appeared to him again and said, “I am God All-Powerful. If you obey me and always do right, I will keep my solemn promise to you and give you more descendants than can be counted.” Abram bowed with his face to the ground, and God said: I promise that you will be the father of many nations. So now I'm changing your name from Abram to Abraham. I will give you a lot of descendants, and they will become great nations. Some of them will even be kings. I will always keep the promise I have made to you and your descendants, because I am your God and their God. I will give you and them the land in which you are now a foreigner. I will give the whole land of Canaan to your family forever, and I will be their God. Abraham, you and all future members of your family must promise to obey me. As the sign that you are keeping this promise, you must circumcise every man and boy in your family. From now on, your family must circumcise every baby boy when he is eight days old. You must even circumcise any man or boy you have as a slave, both those born in your homes and those you buy from foreigners. This will be a sign that my promise to you will last forever. Any man who isn't circumcised hasn't kept his part of the promise and cannot be one of my people. Abraham, from now on your wife's name will be Sarah instead of Sarai. I will bless her, and you will have a son by her. She will become the mother of nations, and some of her descendants will even be kings. Abraham bowed with his face to the ground and thought, “I am almost 100 years old. How can I become a father? And Sarah is 90. How can she have a child?” So he started laughing. Then he asked God, “Why not let Ishmael inherit what you have promised me?” But God answered: No! You and Sarah will have a son. His name will be Isaac, and I will make an everlasting promise to him and his descendants. However, I have heard what you asked me to do for Ishmael, and so I will also bless him with many descendants. He will be the father of twelve princes, and I will make his family a great nation. But your son Isaac will be born about this time next year, and the promise I am making to you and your family will be for him and his descendants forever. God finished speaking to Abraham and then left. On that same day Abraham obeyed God by circumcising Ishmael. Abraham was also circumcised, and so were all the other men and boys in his household, including his servants and slaves. He was 99 years old at the time, and his son Ishmael was 13.