But God said, “No. Your wife Sarah will bear you a son and you will name him Isaac. I will keep my covenant with him and with his descendants forever. It is an everlasting covenant.
One of them said, “Nine months from now I will come back, and your wife Sarah will have a son.” Sarah was behind him, at the door of the tent, listening.
Then God gave to Abraham the ceremony of circumcision as a sign of the covenant. So Abraham circumcised Isaac a week after he was born; Isaac circumcised his son Jacob, and Jacob circumcised his twelve sons, the famous ancestors of our race.
It was faith that made Abraham able to become a father, even though he was too old and Sarah herself could not have children. He trusted God to keep his promise.
Then I took Abraham, your ancestor, from the land across the Euphrates and led him through the whole land of Canaan. I gave him many descendants. I gave him Isaac,