Genesis 18:10-12

10Then the LORD said, “I will surely return to you at this time next year, and your wife Sarah will have a son!”

Now Sarah was behind him, listening at the entrance to the tent. 11And Abraham and Sarah were already old and well along in years; Sarah had passed the age of childbearing. 12So she laughed to herself, saying, “After I am worn out and my master is old, will I now have this pleasure?”