At first glance, the Parsha of Bemidbar Sinai appears to be nothing more than a list of names, places, numbers, and roles. The Parsha describes who did what, where it was done, and how they were to do it. The formation of the Shevatim when traveling, a census of Bnai Yisrael, and the names and roles of all the groups of Leviim are all in this Parsha, details that Hashem felt necessary to tell us. Clearly there is something to learn from each of these things, but there is another aberration in the Parsha that catches the eye without any heavy searching.
In the very beginning of the third Perek, the Torah lists the Kohanim: Aharon and his sons Nadav, Avihu, Elazar, and Itamar. Rav Shamshon Raphael Hirsch points out that anyone who knows how to read the cantillation (Trop) of the Pesukim will notice an oddity: the reader sounds as if he is pausing at the mention of Nadav’s name (with an אתנחתא), and then lingering over Avihu (with a זקף גדול). Aware that Aharon’s older sons died, the Torah pauses at their names to remind the reader what happened to them.
What is fascinating is the wording of that particular Pasuk, “On the day that Hashem spoke to Moshe on Har Sinai” (3:1). Aharon did have two sons, but the Torah (3:4) recounts that Nadav and Avihu brought a “strange fire” before Hashem and were taken from this earth. This would imply that the accounting recorded here was taken before the events of the Chanukat Hamishkan (inauguration of the Mishkan), during which time Nadav and Avihu lost their lives.
Immediately following the Pesukim regarding Aharon’s family, the Torah talks about the rest of Shevet Levi and their role, since they were not counted with the other Shevatim. The sixth and seventh Pesukim in this Perek describe the role of the Leviim as caretakers and guards of the Mishkan, serving in those basic janitorial posts that every building, no matter how holy, requires. We first saw that this was their role at the Chanukat Hamishkan; it was two Leviim who were called upon to remove the bodies of Nadav and Avihu from the Mishkan. When something in the Mishkan needs to be done, you can always call a Levi.
The word that the Torah uses, שמר, is most commonly translated as “guard.” But from whom are the Leviim guarding the Mishkan? The camp of Bnai Yisrael is not in a bad neighborhood that would force Hashem to install a security system or buy a guard dog. What could threaten the Mishkan that required protection from the Leviim?
One answer may be found in the juxtaposition of the description of the role of Shevet Levi to the reminder of what happened to Nadav and Avihu. Perhaps the Torah is suggesting that the tragedy of Nadav and Avihu might never have happened if there was a group to guard against those who wished to enter the Mishkan for unacceptable reasons. Had Leviim been guarding the Mishkan then, they would not have allowed any “strange fires” into the Heichal.
The Torah is providing us with an important message on how to guard against sin. Sin can come as a result of bad judgement, over-zealousness, or simple mistakes. Hashem is telling us to set up safeguards, to the best of our abilities, to prevent wrongdoing on any level.