Genesis 18:10
"And he said, I will certainly return unto thee according to the time of life; and, lo, Sarah thy wife shall have a son. And Sarah heard it in the tent door, which was behind him."
Cross References (ranked by relevance)
For Sarah conceived, and bare Abraham a son in his old age, at the set time of which God had spoken to him.
But my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year.
And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant, and with his seed after him.
And I will bless her, and give thee a son also of her: yea, I will bless her, and she shall be a mother of nations; kings of people shall be of her.
But the angel said unto him, Fear not, Zacharias: for thy prayer is heard; and thy wife Elisabeth shall bear thee a son, and thou shalt call his name John.
But he who was of the bondwoman was born after the flesh; but he of the freewoman was by promise.
And the angel of the LORD said unto her, I will multiply thy seed exceedingly, that it shall not be numbered for multitude.
Now we, brethren, as Isaac was, are the children of promise.