Genesis 17:14-17
English Standard Version
15And God said to Abraham, "As for Sarai your wife, you shall not call her name Sarai, but Sarah shall be her name.
16I will bless her, and moreover, I will give you a son by her. I will bless her, and she shall become nations; kings of peoples shall come from her."
17Then Abraham fell on his face and laughed and said to himself, "Shall a child be born to a man who is a hundred years old? Shall Sarah, who is ninety years old, bear a child?"