Luke 1:7, 18, 36

But they were childless since Elizabeth was barren, and now they both were quite old.

Zechariah asked the angel, “How do you expect me to believe this? I’m an old man and my wife is too old to give me a child. What sign can you give me to prove this will happen?”

What’s more, your aged aunt, Elizabeth, has also become pregnant with a son. The ‘barren one’ is now in her sixth month.