According to the custom of the priest's office, his lot was to burn incense when he went into the temple of the Lord. His lot was, etc. - We are informed in the Talmud, that it was the custom of the priests to divide the different functions of the sacerdotal office among themselves by lot: and, in this case, the decision of the lot was, that Zacharias should at that time burn the incense before the Lord, in the holy place.
Related Commentaries of Luke 1:9
Luke 1:9
9 According to the custom of the priest's office, his lot was to burn incense when he went into the temple of the Lord.