"In the days of Herod . . . there was a priest named Zacharias . . . and he had a wife from the daughters of Aaron, and her name was Elizabeth. They were both righteous in the sight of God, walking blamelessly in all the commandments and requirements of the Lord. But they had no child, because Elizabeth was barren and they were both advanced in years.
Now it happened that while he was performing his priestly service before God in the appointed order of his division, according to the custom of the priestly office, he was chosen by lot to enter the temple of the Lord and burn incense. And the whole multitude of the people were in prayer outside at the hour of the incense offering. And an angel of the Lord appeared to him, standing to the right of the altar of incense. Zacharias was troubled when he saw the angel, and fear gripped him. But the angel said to him, 'Do not be afraid, Zacharias, for your petition has been heard, and your wife Elizabeth will bear you a son, and you will give him the name John. For you will have joy and gladness, and many will rejoice at his birth. For he will be great in the sight of the Lord . . . it is he who will go as a forerunner before Him in the spirit and power of Elijah . . . so as to make ready a people prepared for the Lord.'" - Luke 1:5017, NASB (emphasis mine)