Genesis 17
15 Ref And God said, As for Sarai, your wife, from now her name will be not Sarai, but Sarah.
16 Ref And 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.
17 Ref Then 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?