Charles Ellicott Commentary Luke 1:9

"according to the custom of the priest`s office, his lot was to enter into the temple of the Lord and burn incense." — Luke 1:9 (ASV)

His lot was to burn incense.—The order of the priestly courses, as has been said, was one of rotation. The distribution of functions during the week was determined by lot. The offering of incense, symbolizing as it did the priestly work of presenting the people's prayers and joining his own with them (Psalms 141:2; Revelation 5:8), was the most distinctive of all priestly acts (2 Chronicles 26:18). At such a moment, all the hopes of one who looked for the Christ as the consolation of Israel would gather into one great intercession.

Into the temple of the Lord—that is, the Holy Place, into which only priests could enter.