When Abram was ninety-nine years old, the LORD appeared to him and said, "I am God Almighty; serve me faithfully and live a blameless life.
I will make a covenant with you, by which I will guarantee to make you into a mighty nation."
At this, Abram fell face down in the dust. Then God said to him,
"This is my covenant with you: I will make you the father of not just one nation, but a multitude of nations!
What's more, I am changing your name. It will no longer be Abram; now you will be known as Abraham, for you will be the father of many nations.
References for Genesis 17:5
I will give you millions of descendants who will represent many nations. Kings will be among them!"
"I will continue this everlasting covenant between us, generation after generation. It will continue between me and your offspring forever. And I will always be your God and the God of your descendants after you.
References for Genesis 17:7
Yes, I will give all this land of Canaan to you and to your offspring forever. And I will be their God."
"Your part of the agreement," God told Abraham, "is to obey the terms of the covenant. You and all your descendants have this continual responsibility.
This is the covenant that you and your descendants must keep: Each male among you must be circumcised;
the flesh of his foreskin must be cut off. This will be a sign that you and they have accepted this covenant.
Every male child must be circumcised on the eighth day after his birth. This applies not only to members of your family, but also to the servants born in your household and the foreign-born servants whom you have purchased.
All must be circumcised. Your bodies will thus bear the mark of my everlasting covenant.
Anyone who refuses to be circumcised will be cut off from the covenant family for violating the covenant."
Then God added, "Regarding Sarai, your wife -- her name will no longer be Sarai; from now on you will call her Sarah.
References for Genesis 17:15
And I will bless her and give you a son from her! Yes, I will bless her richly, and she will become the mother of many nations. Kings will be among her descendants!"
Then Abraham bowed down to the ground, but he laughed to himself in disbelief. "How could I become a father at the age of one hundred?" he wondered. "Besides, Sarah is ninety; how could she have a baby?"
And Abraham said to God, "Yes, may Ishmael enjoy your special blessing!"
But God replied, "Sarah, your wife, will bear you a son. You will name him Isaac, and I will confirm my everlasting covenant with him and his descendants.
References for Genesis 17:19
As for Ishmael, I will bless him also, just as you have asked. I will cause him to multiply and become a great nation. Twelve princes will be among his descendants.
But my covenant is with Isaac, who will be born to you and Sarah about this time next year."
That ended the conversation, and God left Abraham.
On that very day Abraham took his son Ishmael and every other male in his household and circumcised them, cutting off their foreskins, exactly as God had told him.
Abraham was ninety-nine years old at that time,
and Ishmael his son was thirteen.
Both were circumcised the same day,
along with all the other men and boys of the household, whether they were born there or bought as servants.