The rebellion of Korach and his supporters was based, among other factors, on the special status of the tribe of Levi, who were singled out to serve Hashem in the Mishkan. Korach felt that his division of the tribe the Yitzhar branch of the sons of Kehat was slighted in the apportioning of tribal honors (see Rashi on 16:1), and this prompted him to oppose Moshe’s authority. Moshe is disappointed and upset that his fellow-Leviim have mistaken duty for privilege:
And Moshe said to Korach, “Listen, please, you sons of Levi. Is
it a small thing for you that [Hashem] the G-d of Israel has separated you from
the community of Israel to draw you near to Him, to perform the service of the
Mishkan of Hashem, and to stand before the community to serve them? And He
brought you near, you and all your brethren, the children of Levi, with you; and
still you request priesthood?” (Bamidbar 16:8-9)
And Hashem said to Aharon, “You shall have no inheritance in their land, and neither shall you have any portion among them; I am your portion and your inheritance among the Children of Israel” (18:20).
Here, the Kohanim are excluded from inheritance, and the rest of the tribe of Levi are similarly addressed in verse 24. The Torah repeats this exclusion in Devarim (18:1-2):
There shall not be for the Kohanim, the Leviim all the tribe
of Levi a portion and inheritance with Israel; the fire-offerings of Hashem
and His inheritance shall they eat. And an inheritance shall he not have in the
midst of his brethren; Hashem is his inheritance, as He spoke to him.
The word BETOCHAM (among them), says Ohr HaChaim, serves to
limit the prohibition: The Leviim may not take, nor may they be given, some of
the spoils of war when they are divided among the tribes; however, if afterwards
the people wish to send the Leviim gifts, the Leviim may accept them.
…because they were separated to worship Hashem, to serve Him and to teach His correct ways and His righteous laws to the public, as it says, They will teach Your laws to Yaakov and Your teachings to Israel (Devarim 33:10). Therefore, they are separated from the ways of the world: they do not engage in war as the rest of Israel, nor do they inherit, nor do they take possession for themselves through their own power. Rather, they are Hashem’s regiment, as it says, Bless Hashem His regiment (ibid, v.11). And He, may He be blessed, benefits them, as it says, I am your portion and your inheritance.
In order to enable them to serve Hashem “full-time,” the Leviim
are freed from these day-to-day concerns.
He is your pleasure in the service of Hashem and in the
perseverance of the Torah, and there is no love like the love of Hashem and the
love of the Torah . . . and all external pleasures are obstacles to the pleasure
of the soul.