18 And Zachariah said to the angel: By what sign shall I know this? for I am old, and my wife is advanced in years.
Luke 1:18 Cross References - Anderson
Luke 1:7
7 And they had no child, because Elizabeth was barren, and they were both advanced in years.
Luke 1:34
34 But Mary said to the angel: How shall this be, since I know not a man?
Romans 4:19
19 And not being weak in faith, he considered not his own body, which was already dead, (for he was about a hundred years old,) nor the deadness of Sarah's womb;