Luke 1:7-11

But they had no child, because Elizabeth was barren, and they were both well advanced in years. So it was, that while he was serving as priest before God in the order of his division, according to the custom of the priesthood, his lot fell to burn incense when he went into the temple of the Lord. And the whole multitude of the people was praying outside at the hour of incense. Then an angel of the Lord appeared to him, standing on the right side of the altar of incense.