Sifrei Mitzvot para sa Mga Bilang 18:3

To watch over this edifice continually, as it is said, “…. but thou and thy sons with thee shall minister before the tabernacle of the testimony” (Num. 18:2).

The commandment to guard the Temple: That the priests and the Levites were commanded to guard the Temple and walk around it constantly the whole night, on each and every night (see R. Chaim Heller — Sefer HaMitzvot, Positive Commandments 22) — and this guarding is to honor it, to exalt it and to glorify it, and not from there being any fear of the enemy, God forbid — as it is stated (Numbers 18:4), “and they shall guard the guarding of the Tent of Meeting.” And the language of Sifrei Bamidbar 116 is “‘And you and your sons with you will be in front of the Tent of Testimony’ (Numbers 18:2) — the priests inside and the Levites only outside”; meaning to say to guard it and to walk around it. And in the Mekhilta (Sifrei Zuta on Numbers 18:4), they said, “‘And they shall guard the guarding of the Tent of Meeting’ — I only know of a positive commandment, etc.” Behold, it is elucidated that its guarding is a positive commandment. And there it says another greatness of the Temple is that it has guards — “A palace that has guards is not similar to a palace that does not have guards.” And it is known that the palace is a name for the sanctuary.

What I have already written several times is from the roots of the commandment — that the glory of the [Temple] brings awe to the heart of people. And in our coming there to request supplication and pardon from the Master of All, [our] hearts will soften to quick repentance; and like the matter that we said at length in the Order of VeAtah Tetsaveh (Sefer HaChinukh 98). And it is from the glory of the [Temple] to appoint guards for it, like the way of great kings in the world that do such; and as it comes in the Mekhilta, “It is not similar, etc.,” as is written adjacently (above).