פּירוש אויף במדבר 17:5

ולא יהיה כקרח means in order that he be not as Korah.

“And he shall not be like Korah and his congregation, etc.” Rashi explains that he will not be afflicted with tzara’at like Moses was afflicted with tzara’at on his hand (Sanhedrin 110a), and the word lo [to him] refers to one who disputes the priesthood. Here the child asks: What is the connection between Moses’ tzara’at and one who disputes the priesthood? It would have been more appropriate to bring as evidence Miriam’s tzara’at, which was similar in nature to Korah’s dispute, for his dispute over the priesthood stemmed from his challenge to Moses’ prophecy — the Lord has not sent you — and of this kind was Miriam’s tzara’at, as she said, Has the Lord spoken only through Moses? Has He not spoken through us as well? (Numbers 12:2). Similarly, Korah said, For all the congregation, all of them are holy (Numbers 16:3) — not only you alone heard at Mount Sinai, I am and You shall have no other gods. But what relevance does Moses’ hand afflicted with tzara’at have to Korah’s dispute?

THAT HE BE NOT AS KORACH, AND AS HIS COMPANY, AS THE ETERNAL SPOKE BY THE HAND OF MOSES ‘LO.’ “The word lo [literally: ‘to him’] is like alav (‘about him’), that is, about Korach. And what is the meaning of by ‘the hand’ of Moses, and why is it not written ‘unto Moses’ [as is written elsewhere]? It is a hint to those who dispute the priesthood, that they will be stricken with leprosy, just as Moses was stricken [with it] on ‘his hand.’¹⁷⁰Exodus 4:6. It was for this reason that Uzziah [king of Judah] was stricken with leprosy [when he attempted to usurp the function of the priests and to offer incense].¹⁷¹II Chronicles 26:19. And according to the plain meaning of Scripture,¹⁷²This interpretation is not found in our texts of Rashi. It is mentioned, however, by Rambam in his Book of the Commandments (see my translation, “The Commandments,” Vol. II, the Eighth Principle, p. 393). [the interpretation is as follows: if anybody disputes the priesthood and claims it for himself, his punishment] will not be that of being swallowed up and burnt, as happened to Korach and his company; instead, [his punishment] will be like that which Moses received on his hand when it was stricken with leprosy. And some scholars¹⁷³This interpretation is brought [in our editions of Rashi], by Rashi himself in his own name at the very beginning of the verse. It is thus obvious that Ramban had a completely different text of Rashi before him here. interpret [the verse to mean]: that no common man, that is not of the seed of Aaron, draw near to burn incense before the Eternal¹⁷⁴Verse 5 before us. — as the Eternal spoke by the hand of Moses with regard to Aaron, that he and his sons should be priests, and not a layman.” This is Rashi’s language. The correct interpretation is that [the word lo (to him)] refers to Eleazar who is mentioned [at the beginning of the section], when Scripture said, Speak unto Eleazar the son of Aaron the priest etc.,¹⁷⁵Verse 2. and the correct order [in meaning] of the verses [before us] is as follows: And Eleazar the priest took the copper censers wherewith they that were burnt had offered, and they beat them out for a covering of the altar¹⁷⁶Verse 4. — as the Eternal spoke to him by the hand of Moses¹⁷⁴Verse 5 before us. — to be a memorial unto the children of Israel etc.¹⁷⁴Verse 5 before us.