The end of Parshat Korach is filled with laws related to the Kohanim and Leviim. They also serve to give us a glimpse of their service in the Temple. There is a positive commandment to “guard the Temple.” This refers to the specific ongoing duties to fulfill this Mitzva.
There was a requirement for twenty-four Levites to be posted at twenty-four entrances and locations to the Temple. Three Kohanim needed to guard the entrance to the Heichal. This was the building that housed the Holy Ark, the Menora, the incense altar, and the Table and showbread.
They were on duty all night long, and were visited by a monitor, who walked around carrying a torch, to be certain everyone was doing their duty. If one of the guards fell asleep, he might set their clothes on fire to wake them! If they were doing their job properly, they would greet this man known as איש הר הבית, the man of the Temple Mount, with the words, “Shalom to you, Temple Mount man.”
The purpose of this guarding was to impress upon the nation, the importance of this holy place. When any building is surrounded by armed guards, it is clear that this must be a special. This created reverence and awe for the holy Temple in Jerusalem.