"And it came to pass, that 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 burn incense when he went into the temple of the Lord."
Those who were outside knew how long it would take to burn incense and offer the morning prayer, therefore when too much time had passed they were troubled by the delay. (Luke 1: 21.)
The prayer he offered was set, given each day as part of offering incense in the Holy Place, and is as follows:
When the angel appeared and said, "Fear not, Zacharias; for thy prayer is heard" (Luke 1: 13), the prayer asked for "the light of [God's] countenance" to shine again upon Israel. The promised son (to be named "John"--Luke 1: 13) was to "go before him in the spirit and power of Elias." (Luke 1: 17.) The One before whom John was to go was "the light of [God's] countenance" or, in other words, Jehovah. John was to be Elias to precede and prepare the way for Jehovah.
Following his birth, John was "ordained by the angel of God at the time he was eight days old unto this power, to overthrow the kingdom of the Jews, and to make straight the way of the Lord before the face of his people, to prepare them for the coming of the Lord, in whose hand is given all power." (D&C 84: 28.) He prepared the way, was imprisoned and beheaded. Then he appeared with Moses on the Mount of Transfiguration. (JST-Mark 9: 4; Matt. 17: 2-3, 13.) Moses opened, and John closed, the prior dispensation and met with Christ as the founder of the new dispensation.
John was as great a prophet as ever lived. The Lord said he was "more than a prophet." (Luke 7: 24-28.) Foretold in prophecy, born to bring "the light of God's countenance" back to Israel, fulfilling an angel's promise, named by heaven, ordained at eight days, sent to close one and open another dispensation, slain for his testimony, and then called to minister as an angel to the Lord on the Mount of Transfiguration, John was "more than a prophet."