Luke 1:9 WEB

⁷  But they had no child, because Elizabeth was barren, and they both were well advanced in years.

⁸  Now it happened, while he executed the priest's office before God in the order of his division,

⁹  according to the custom of the priest's office, his lot was to enter into the temple of the Lord and burn incense.

¹⁰  The whole multitude of the people were praying outside at the hour of incense.

¹¹  An angel of the Lord appeared to him, standing on the right side of the altar of incense.