פּירוש אויף במדבר 16:7

רב לכם בני לוי means, “It is a great (an important) thing that I have told you, ye sons of Levi”). But were they not fools in that although he so sternly warned them they nevertheless undertook to offer! They, however, sinned against their own souls (i.e., they were regardless of their lives) as it is said, (17:3) “the censers of these sinners against their souls”. — But Korah who certainly was a clever (lit., open-eyed) man, what reason had he to commit this folly? His mind’s eye misled him. He saw by prophetic vision a line of great men (more lit., a great chain) descending from him, amongst them the prophet Samuel who was equal in importance to Moses and Aaron together (cf. Psalms 99:6: משה ואהרן בכהניו ושמואל בקראי שמו), and he said to himself, “On his account I shall escape the punishment”. And he further saw twenty-four Mishmars (shifts of Levites who formed the Temple Choir) arising among his grand-children, all of them prophesying by the Holy Spirit, — as it is said, (I Chronicles 25:5) “All these (prominent musicians) were sons of Heiman” (Heiman was a descendant of Korah; cf. I Chronicles 6:18—23). — He said, “Is it possible that all this dignity is to arise from me and I shall remain silent (be myself of no importance)?” On this account he joined the others in order to attain to that prerogative, because he had indeed heard from the mouth of Moses that all else of them would perish and one would escape: "He whom the Lord will choose will be holy". He mistakenly applied this to himself. But he had not seen correctly, for his sons repented of their rebellious attitude and therefore did not die at that time (cf. Numbers 26:11), and it was from them that Samuel and the Levitical singers were descended. Moses, however, foresaw this. (Midrash Tanchuma, Korach 5).

הוא הקדוש, only he is the one accorded the title “holy.” In the test Moses proposes there could be only one winner. Moses made this statement in order to frighten his listeners (as they would become aware of the enormity of the gamble they were going to involve themselves in) and knowing this they might repent and not lose their lives. Just as G’d does not want the sinner to die but to repent, so Moses offered these people the chance to retract and thereby save their lives. (compare Ezekiel 18,32).

רב לכם בני לוי, “You have gone too far, O sons of Levi!” Moses meant that G’d had already given the Levites plenty. In the following verse he spells out precisely what it was that G’d had given the Levites.

רב לכם means, a great responsibility have you taken upon yourselves in rebelling against the Holy One, blessed be He.