15And God said, As for Sarai, your wife, from now her name will be not Sarai, but Sarah.
16And I will give her a blessing so that you will have a son by her: truly my blessing will be on her, and she will be the mother of nations: kings of peoples will be her offspring.
17Then Abraham went down on his face, and laughing, said in his heart, May a man a hundred years old have a child? will Sarah, at ninety years old, give birth?
18And Abraham said to God, If only Ishmael's life might be your care!
19And God said, Not so; but Sarah, your wife, will have a son, and you will give him the name Isaac, and I will make my agreement with him for ever and with his seed after him.
20As for Ishmael, I have given ear to your prayer: truly I have given him my blessing and I will make him fertile and give him great increase; he will be the father of twelve chiefs, and I will make him a great nation.
21But my agreement will be with Isaac, to whom Sarah will give birth a year from this time.
