Korach, Datan and Aviram and 250 leaders of Israel rebel against the authority of Moshe and Aharon. The rebellion results in their being swallowed by the earth. Many resent their death and blame Moshe. G-d's "anger" is manifested by a plague that besets the nation, and many thousands perish. Moshe intercedes once again for the people. He instructs Aharon to atone for them and the plague stops. Then G-d commands that staffs, each inscribed with the name of one of the tribes, be placed in the Mishkan. In the morning, the staff of Levi, bearing Aharon's name, sprouts buds, blossoms and yields ripe almonds. This provides Divine confirmation that Levi's tribe is chosen for priesthood and verifies Aharon's position as Kohen Gadol, High Priest. The specific duties of the Levi'im and Kohanim are stated. The Kohanim were not to be landowners, but were to receive their sustenance from the tithes and other mandated gifts brought by the people. Also taught in this week's Parsha are laws of the first fruits, redemption of the firstborn, and other offerings.
The Pot Calling the Kettle Black
Korach said: It is too much from you! For the entire assembly – all of them – are holy, and G-d is among them; why do you exalt yourselves over the congregation of Gd? Moshe heard and he fell on his face… (16:4)
The Talmud deduces that Moshe fell on his face because Korach was accusing him of adultery. (Sanhedrin 109)
It’s difficult to see how Moshe recognized from Korach’s words the slur of immorality.
The halacha states (Choshen Mishpat 500) that if in the midst of an argument one says to the other, “I am not evil!”, what he is really saying is: “I’m not evil — but you are!”
When Korach said, “For the entire assembly – all of them – are holy…” he meant “we are all holy but you are the antithesis of holiness — you are depraved!”
Source: Mishkanot Yaakov HaSefaradi