God said, “No, Sarah your wife is going to bear you a son, and you will name him Isaac. I will confirm my covenant with him as a perpetual covenant for his descendants after him.
Then the Lord’s angel said to her, “You are now pregnant and are about to give birth to a son. You are to name him Ishmael, for the Lord has heard your painful groans.
I will bless her and will give you a son through her. I will bless her and she will become a mother of nations. Kings of countries will come from her!”
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.
Stay in this land. Then I will be with you and will bless you, for I will give all these lands to you and to your descendants, and I will fulfill the solemn promise I made to your father Abraham.
When the rainbow is in the clouds, I will notice it and remember the perpetual covenant between God and all living creatures of all kinds that are on the earth.”
By faith, even though Sarah herself was barren and he was too old, he received the ability to procreate, because he regarded the one who had given the promise to be trustworthy.