Genesis 17:15-17

15And God said to Abraham, As for Sarai thy wife, thou shalt not call her name Sarai, but Sarah shall her name be .1 16And I will bless her, and give thee a son also by her: yea, I will bless her, and she shall be a mother of nations; kings of people shall come from her.2 17Then Abraham fell upon his face, and laughed, and said in his heart, Shall a child be born to him that is an hundred years old? and shall Sarah, who is ninety years old, bear?