Genesis 18:9-14

Then they said to him, “Where is Sarah your wife?” So he said, “Here, in the tent.” And He said, “I will certainly return to you according to the time of life, and behold, Sarah your wife shall have a son.” (Sarah was listening in the tent door which was behind him.) Now Abraham and Sarah were old, well advanced in age; and Sarah had passed the age of childbearing. Therefore Sarah laughed within herself, saying, “After I have grown old, shall I have pleasure, my lord being old also?” And the LORD said to Abraham, “Why did Sarah laugh, saying, ‘Shall I surely bear a child, since I am old?’ Is anything too hard for the LORD? At the appointed time I will return to you, according to the time of life, and Sarah shall have a son.”