389. Trading Places: The prohibition against a Levite doing a kohein’s work (and vice versa)

The kohanim and Leviim (priests and Levites) were both descendants of the Tribe of Levi and both were given jobs in the Temple, but they were discrete and distinct. The kohanim were not to do the job of the Leviim and vice versa. From the first part of our verse, it would seem that only the Leviim were prohibited from doing the work of the kohanim; the rest of the verse – “so that they shall not die, neither they nor you” – makes it apparent that it’s a two-way street. (The death referred to in the verse is a spiritual one, not capital punishment at the hands of the court. Actually, only the Leviim incurred a Heavenly death penalty for doing the work of the kohanim; the kohanim incurred lashes for doing the work of the Leviim – see Sefer HaMitzvos Negative #72 for a full explanation as to how this is known.)

In Talmud Arachin (11b), it is related how Rabbi Yehoshua ben Chananya (who was a Levi) wanted to assist his friend Rabbi Yochanan ben Gudgeda (who was a kohein) in locking up the Temple for the night. Rabbi Yochanan warned him off because doing so would be a violation of this mitzvah.

The reason for this mitzvah is that the kohanim and the Leviim were each entrusted with particular jobs, each of which is very literally a sacred responsibility. Each group must ensure special diligence in his assigned role. The traffic reporter and the weather girl might switch jobs for a day because it’s fun, but the ability to do so on a whim says that the jobs aren’t really all that important. You never see the Secretary of State and the Chief Justice of the Supreme Court trading places for a day. If kohanim and Leviim just traded off jobs whenever they felt like it, it would lead to them slacking off, assuming that their partner would pick up the slack. The result, of course, would be that certain jobs would end up going undone.

This mitzvah applies to kohanim and Leviim in Temple times. In the Talmud, it is discussed in tractate Arachin on page 11b. It is codified in the Mishneh Torah in the third chapter of Hilchos Klei HaMikdash. This mitzvah is #72 of the 365 negative mitzvos in the Rambam’s Sefer HaMitzvos.