Genesis 17:15-19

Thomson(i) 15 Moreover God said to Abraham, "Sara thy wife shall not be called Sara. Her name shall be Sarah. 16 And I will bless her and give thee a son by her. And I will bless him. And he shall become nations, and from him there shall be kings of nations." 17 Upon this Abraham fell on his face and smiled, and said in his heart, To him who is in his hundredth year shall a son be born? and shall Sarah bring forth in her ninetieth year? 18 And Abraham said to God, Let this Ismael live before thee. 19 Whereupon God said to Abraham, Nay, behold Sarah thy wife shall bear thee a son, and thou shalt call his name Isaak. And I will establish my covenant with him for an everlasting covenant to be his God and the God of his seed after him.