When Abram was 99 years old, the LORD appeared to Abram and said to him, "I am El Shaddai. Walk with me and be trustworthy.
References for Genesis 17:1
I will make a covenant between us and I will give you many, many descendants."
Abram fell on his face, and God said to him,
"But me, my covenant is with you; you will be the ancestor of many nations.
And because I have made you the ancestor of many nations, your name will no longer be Abram but Abraham.
References for Genesis 17:5
I will make you very fertile. I will produce nations from you, and kings will come from you.
I will set up my covenant with you and your descendants after you in every generation as an enduring covenant. I will be your God and your descendants' God after you.
I will give you and your descendants the land in which you are immigrants, the whole land of Canaan, as an enduring possession. And I will be their God."
God said to Abraham, "As for you, you must keep my covenant, you and your descendants in every generation.
This is my covenant that you and your descendants must keep: Circumcise every male.
You must circumcise the flesh of your foreskins, and it will be a symbol of the covenant between us.
On the eighth day after birth, every male in every generation must be circumcised, including those who are not your own children: those born in your household and those purchased with silver from foreigners.
Be sure you circumcise those born in your household and those purchased with your silver. Your flesh will embody my covenant as an enduring covenant.
Any uncircumcised male whose flesh of his foreskin remains uncircumcised will be cut off from his people. He has broken my covenant."
God said to Abraham, "As for your wife Sarai, you will no longer call her Sarai. Her name will now be Sarah.
I will bless her and even give you a son from her. I will bless her so that she will become nations, and kings of peoples will come from her."
Abraham fell on his face and laughed. He said to himself, Can a 100-year-old man become a father, or Sarah, a 90-year-old woman, have a child?
To God Abraham said, "If only you would accept Ishmael!"
But God said, "No, your wife Sarah will give birth to a son for you, and you will name him Isaac. I will set up my covenant with him and with his descendants after him as an enduring covenant.
References for Genesis 17:19
As for Ishmael, I've heard your request. I will bless him and make him fertile and give him many, many descendants. He will be the ancestor of twelve tribal leaders, and I will make a great nation of him.
But I will set up my covenant with Isaac, who will be born to Sarah at this time next year.
When God finished speaking to him, God ascended, leaving Abraham alone.
Abraham took his son Ishmael, all those born in his household, and all those purchased with his silver—that is, every male in Abraham's household—and he circumcised the flesh of their foreskins that same day, just as God had told him to do.
Abraham was 99 years old when he circumcised the flesh of his foreskin,
and his son Ishmael was 13 years old when the flesh of his foreskin was circumcised.
That same day Abraham and his son Ishmael were circumcised.
All the men of his household, those born in his household and those purchased with silver from foreigners, were circumcised with him.