Genesis 18:6, 9-10

So Abraham hurried into the tent to Sarah and said, “Quickly, make ready three measures of fine meal; knead it and make cakes.”

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.)