Quotation do Liczb 16:7

ויקומו לפני משה ואנשים מבני ישראל חמשים ומאתים, all these who ganged up on Moses and Aaron were from Korach’s own tribe, i.e. Levites. This is the meaning of Moses saying to them: “רב לכם בני לוי, “enough for you Levites, etc.” (verse 7), as well as when he again addressed them as בני לוי in verse 8, i.e. stressing that the people he was speaking to were all Levites. Perhaps these Levites had been under the impression that their whole tribe had been meant to be priests and that Moses had highhandedly decided to bestow this honour only on his brother Aaron.