Abraham bowed down with his face to the ground. But inside he was laughing, asking himself, “How on earth could I have a son at the age of one hundred? How could Sarah have a child when she is ninety?”
When Rachel realized she was unable to give Jacob any children she was jealous of her sister. She complained to Jacob, “I'll die if you don't give me children!”
During the time when Herod was king of Judea, there was a priest called Zechariah, who came from the Abijah priestly division. He was married to Elizabeth, who was also descended from Aaron the priest.
His trust in God didn't weaken even though he thought his body was practically dead (he was around a hundred years old), and knew that Sarah was too old to have children.
By her trust in God even Sarah herself was given the ability to conceive a child though she was too old, because she trusted God who had made the promise.