Genesis 17:15-19 And God said unto Abraham: 'As for Sarai thy wife, thou shalt not call her name Sarai, but Sarah shall her name be.

JPS_ASV_Byz⁽ⁱ⁾ ¹⁵ And God said unto Abraham: 'As for Sarai thy wife, thou shalt not call her name Sarai, but Sarah shall her name be. ¹⁶ And I will bless her, and moreover I will give thee a son of her; yea, I will bless her, and she shall be a mother of nations; kings of peoples shall be of her.' ¹⁷ Then Abraham fell upon his face, and laughed, and said in his heart: 'Shall a child be born unto him that is a hundred years old? and shall Sarah, that is ninety years old, bear?' ¹⁸ And Abraham said unto God: 'Oh that Ishmael might live before Thee!' ¹⁹ And God said: "Nay, but Sarah thy wife shall bear thee a son; and thou shalt call his name Isaac; and I will establish My covenant with him for an everlasting covenant for his seed after him.