Genesis 18:9-12

The men asked Abraham, “Where is your wife Sarah?” “There, in the tent,” said Abraham. Then the LORD said, “I will certainly return to you about this time a year from now. At that time your wife Sarah will have a son.” Sarah was listening at the entrance of the tent which was behind him. Abraham and Sarah were very old. Since Sarah was past the age when women normally have children, she laughed to herself, “My husband and I are too old to have a baby.”