Genesis 18:10-15

10 He said, "I will certainly return to you when the season comes round. Behold, Sarah your wife will have a son."  Sarah heard in the tent door, which was behind him.  11 Now Abraham and Sarah were old, well advanced in age. It had ceased to be with Sarah after the manner of women.  12 Sarah laughed within herself, saying, "After I have grown old will I have pleasure, my lord being old also?"

13 Yahweh said to Abraham, "Why did Sarah laugh, saying, 'Will I really bear a child, yet I am old?'  14 Is anything too hard for Yahweh? At the set time I will return to you, when the season comes round, and Sarah will have a son."

15 Then Sarah denied, saying, "I didn't laugh," for she was afraid."  He said, "No, but you did laugh."