On two occasions in Parshat Korach, Hashem announces His intention to destroy Israel “at this very moment,” i.e., immediately. The Ohr HaChaim, on the first of these instances (Bamidbar 16:21), explains the significance of this expression. After all, it isn’t as though Hashem lacks the power (or the resolve) to wipe out Israel in an instant, so what does the Torah add to our understanding by making this threat explicit?
He cites the Rashi on this verse to the effect that this is the fourth major act of rebellion of all of Israel since their exodus from Mitzrayim. On the previous occasion, with the incident of the spies, Moshe successfully interceded on behalf of Israel inasmuch as he was able to cause the decree of destruction to be deferred over forty years. But in the present situation, all of Israel was already subject to that decree, and now their “stay of execution” was no longer justified. Hashem was informing Moshe and Aharon that there would and could be no further reprieves and that the destruction of such a wicked community was imminent.
So Moshe and Aharon took another approach to the problem. On the first of the two occasions, they say, “Hashem, You rule over all that has life in it – is it consistent with your justice to wipe out an entire community simply because a few people have transgressed against you? Punish only the offenders and forgive the rest who were carried along.” Ramban explains that Moshe and Aharon were able to make an effective separation between the evildoers and those who should not be caught up in the judgment with them. He emphasizes that this is the conduct of great tzaddikim and leaders in every generation: to try to elicit Divine mercy for the overwhelming majority of the people so that the least harm will be done and only a few people can be isolated as evildoers. Ramban says that David HaMelech conducted himself in this way and sometimes even made himself out to be the villain in order to draw the Divine retribution away from the community of Israel.
However, in the second instance in the episode of Korach, after Korach and his coconspirators have already been destroyed and Israel persists in being rebellious, it is no longer credible to make this sort of argument. Korach is gone but the people are still defiantly wicked and the logical conclusion must be, as Hashem says, for Moshe and Aharon to separate themselves from the community so that the righteous will not share the fate of the wicked. Indeed, Hashem approves this approach and amplifies it: “Separate yourself from this wicked community so that I may destroy them” (Bamidbar 17:10). This is the same argument Moshe and Aharon had made previously, but now it’s been turned against Israel – or at least Israel has acted in a way that undermines this argument such that it is no longer effective on our behalf.
At this point Moshe and Aharon have to pivot again in order to find some way to save Israel. If strict reason and justice won’t prevail, then they will array supernatural, spiritual forces in the defense of Israel. Moshe tells Aharon to rush through the camp with a tray of ketoret, to make a division between the infected and dying and those who will live. Once again, we have an act of separation, but the separation is no longer predicated on the relative merits of the groups in question – it is an invocation of some quality inherent in the ketoret. The Ohr HaChaim points out that the people had seen the 250 “gedolim” from the camp of Korach destroyed by bringing ketoret (not to mention Nadav and Avihu on a previous occasion), so Moshe wants to show them that in the right hands, the ketoret can give life and not death – and not only in its proper time and place.
Rashi cites the famous aggadah from Shabbat 89a that the Malach HaMavet, the Angel of Death himself, disclosed this secret to Moshe because, as the Gemara asks, “Otherwise, how would he have known?” Rav Avraham Yitzchak HaKohen Kook made a beautiful observation about the unique power of ketoret and why it alone could be effective in this context. He said that the ketoret connects with the Jewish soul on an exceedingly high and rarified level. At that level of consciousness, there is no longer an awareness of anything wrong or corrupt in our world because somebody who connects on such a high level understands that everything is part of Hashem’s ultimate plan for the good.
Rav Kook doesn’t mention here, but someone who understands reality on such a level also begins to see that all of humanity is really bound together as a cohesive whole, to say nothing of all of Israel who are simply different parts of the same body. The power of ketoret makes the concept of distinctions and even of evil itself irrelevant. Rav Kook’s son Rav Tzvi Yehuda elaborated on this point. He said that the ketoret is the greatest of all the korbanot, and its main purpose is to establish an intrinsic connection between the people who experience it and their Heavenly Father.
The offering of ketoret is reserved for Kohanim alone. The 250 elders in Korach violated this precept and made themselves out to be holier and more spiritually elevated than the rest of Israel – but all they achieved was to make themselves hopelessly unworthy of the life force that had been entrusted to them, and this connection with Hashem that should be fostered by the ketoret was instead ruptured. However, when Aharon, the person properly charged with this responsibility, took the ketoret around the camp and involved all of Israel in the proper performance of the ritual, then everybody was elevated to the level of being truly in congress with the Divine, and it was not necessary for any of those people to die at that time.