The incense procession symbolizes Aaron the priest interceding with incense among the people during the plague after the rebellion of Korah, Dathan, and Abiram, stopping the plague. Incense also represents the prayers of the saints. The priest combines the prayers of the people with those of the saints, lifting them to God as the 24 elders do in the Book of Revelation (“golden bowls full of incense, which are the prayers of the saints”).