Luke 1:8

Now it came to pass, while he executed the priest's office before God in the order of his course, according to the custom of the priest's office, his lot was to enter the temple of the Lord and burn incense.

The necessity for the choice of the priest who would burn incense having been made by lot sprang from the greatness of the number eligible to do this. It was an honor which resulted ever afterward in the title of "rich" for those who received it.

The temple ... refers to the Holy of Holies, the most sacred part of God's temple in the inner area where few men ever entered, and into which an ordinary priest entered only once in a lifetime.