Altar of Incense

What was “the altar of incense”?
It was an altar on which to burn incense that was made from a single block of acacia wood. This altar was 18 inches (45.7 centimeters) long, 18 inches wide, and 36 inches (91.4 centimeters) tall, covered in gold, had corners that stuck out like horns, and two of its sides had gold rings that held two poles used to carry it: “You shall make an altar on which to burn incense. You shall make it of acacia wood. It shall be square, a cubit long and a cubit wide, two cubits high, and its horns of one piece with it. And you shall overlay with pure gold its top, its sides all around, and its horns; and you shall make a gold molding all around it. You shall also make two gold rings for it under its molding on two of its sides; on two opposite sides you shall make them, and they will be holders for the poles with which to carry it. And you shall make poles of acacia wood and overlay them with gold” (Exodus 30:1-5).

Where was the altar of incense?
The sanctuary building inside Jerusalem's temple precinct had two rooms: the holy place, and the most holy place, which housed the ark containing the stone tablets that bore the Ten Commandments. The altar of incense was placed in the holy place directly in front of the veil that covered the entrance to the most holy place: “And you shall put it before the veil that is by the ark of the Testimony, before the mercy seat that is over the Testimony, where I will meet with you” (Exodus 30:6).

What did burning incense on the altar or incense symbolize?
Presenting to God the prayers of the people, including those who were “praying outside at the hour of incense” (Luke 1:10).

When was the “hour of incense” (Luke 1:10)?
Either at sunrise, when the “seven lamps” (Exodus 25:37) were removed from the golden candlestick in the holy place to be cleaned and reloaded with oil, or at sunset, when they were replaced onto the golden candlestick and lit, as God instructed Aaron, the original priest: “Aaron shall burn on it incense of sweet spices; morning by morning when he tends the lamps, he shall burn incense on it. And when Aaron lights the lamps at twilight, he shall burn incense on it, a continual incense before the LORD throughout your generations” (Exodus 30:7-8).

What is meant by Zacharias “serving ... in the order of his division” (Luke 1:8)?
See Division of Abijah.