God replied, “No! Your wife Sarah will give you a son, and you will name him Isaac [He Laughs]. I will make an everlasting promise to him and his descendants.
Then the Messenger of the Lord said to her, “You are pregnant, and you will give birth to a son. You will name him Ishmael [God Hears], because the Lord has heard your cry of distress.
I will make my promise to you and your descendants for generations to come as an everlasting promise. I will be your God and the God of your descendants.
Live here in this land for a while, and I will be with you and bless you. I will give all these lands to you and your descendants. I will keep the oath that I swore to your father Abraham.
Faith enabled Abraham to become a father, even though he was old and Sarah had never been able to have children. Abraham trusted that God would keep his promise.