Now Sarah was behind him, listening at the entrance to the tent. And Abraham and Sarah were already old and well along in years; Sarah had passed the age of childbearing.
Sarah is listening at the tent entrance, and both she and Abraham are old, with Sarah past childbearing age.
It underscores the human impossibility surrounding the promise.
9“Where is your wife Sarah?” they asked. 10Then the LORD said, “I will surely return to you at this time next year, and your wife Sarah will have a son!” 11Now Sarah was behind him, listening at the entrance to the tent. And 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?” 13And the LORD asked Abraham, “Why did Sarah laugh and say, ‘Can I really bear a child when I am old?’ 14Is anything too difficult for the LORD? At the appointed time I will return to you — in about a year — and Sarah will have a son.” 15But Sarah was afraid, so she denied it and said, “I did not laugh.”