ציטירנדיקער פּירוש אויף במדבר 17:25

“And Korah took” - This matter that was in the wilderness of Sinai, when the firstborns were replaced and the Levites were separated,
For the Israelites thought that Moshe our Leader did it according to his own thought, to give greatness to his brother, and also to the sons of Kehat for they are close to him, and all of the Levites that they are his family.
And the Levites conspired against him because they were given to Aaron and his sons.
Datan and Aviram conspired because the firstborn privilege was removed from Reuven their father and given to Yosef; perhaps they suspected that [Moshe did that] for the sake of Yehoshua his servant [who was from Yosef].
Also Korah was a first born, for thus was written.
>And those Heads of the Congregation (edah) were firstborns and they were bringing the olah offerings.
And the proof for this explanation is the miracle of the staff (Bamidbar 17:16-26) that all of Israel saw that Hashem chose the tribe of Levi in place of the firstborns, and therefore it is written (Bamidbar 17:25) “their mutterings ceased,” for the mutterings were about this.
Also Moshe said that “it is not from my own mind” (Bamidbar 26:28), because they suspected that it was from his own mind that he did it.
And further proof is “Hashem did not send me” - for this task - because all the Israelites already believed in him [in general]. Another total proof is “all the congregation are holy” and this is a hint to the firstborns that they are holy, because it is written (shemot 13:2) “sanctify to Me every first born” and they are the priests (Kohanim) that approach Hashem and they are the essence of the whole congregation.

ויקומו לפני משה, ”they orchestrated an uprising against Moses;” Korach’s specific complaint was that seeing that he was the firstborn of his father’s sons, (Exodus 6,21) Aaron instead had been given preferential treatment. Datan, Abiram and On were angry that their tribe had been deprived of the status that should have been accorded to the firstborn of Yaakov their founding father, and that status had been accorded to Joseph and his descendants instead. They believed that this was due to the fact that Joshua from the tribe of Ephrayim, Joseph’s son, had been chosen by Moses to be his closest disciple and valet, the whole tribe had been promoted to special status. They also considered that the leaders of the various tribes had been chosen as they were each firstborns, and that therefore it was clear that their tribe had been deliberately demoted. (Ibn Ezra) Proof that this was their complaint can be seen from Numbers 17,25, where the Torah reports that finally, when Aaron’s staff, i.e. a representative of the tribe of Levi, brought forth a bud that developed into almonds, the Torah reports that these kinds of complaints ceased. They finally realised that G-d had chosen the tribe of Levi rather that Yaakov’s firstborn son Reuven, i.e. that the system of allocating spiritual and material advantages to the firstborn had been replaced by a system of hereditary spiritual background, such as G-d’s having chosen the descendants of three proven patriarchs as His “firstborn” people, a message relayed to Pharaoh at the beginning of Moses’ career. [some of these words are mine. Ed.] On the other hand, Korach rebelled against what appears to be the message of Exodus 13,2, that all the firstborn are to be sanctified, i.e. they were not holy through birth, and he claimed that the entire people of Israel, ever since they had accepted the Torah had become holy, as all had participated in the revelation at Mount Sinai.

AND WE SHALL KNOW THEM. Their intention was to stop people from coming among them, as our Rabbis have said,¹⁷⁴Sanhedrin 109a. for they thought that because of the excellence of their land, which was as the garden of the Eternal,¹⁷⁵Above, 13:10. many will come there, and they despised charity. Lot, however, came to them with his riches and wealth [and was given permission to live in Sodom because] he either asked permission of them, or that they accepted him in honor of Abraham.
Now Scripture testifies that this was the intent of the people of Sodom, as it is said, Behold, this was the iniquity of thy sister Sodom: pride, fullness of bread, and careless ease was in her and in her daughters; neither did she strengthen the hand of the poor and needy.¹⁷⁶Ezekiel 16:49. The verse stating, And the men of Sodom were wicked and sinners against the Eternal exceedingly,¹⁷⁷Above, 13:13. This would seem to indicate that they sinned only against G-d but not against their fellow man. really means that they continued provoking and rebelling against Him with their ease and the oppression of the poor. It is this thought which Scripture expresses by saying, And they were haughty, and committed abomination before Me; therefore I removed them when I saw it.¹⁷⁸Ezekiel 16:50.
In the opinion of our Rabbis,¹⁷⁹Sanhedrin 109a. all evil practices¹⁸⁰Such as blasphemy, bloodshed, etc. (Ibid.) were rampant among them. Yet their fate was sealed because of this sin — i.e., they did not strengthen the hand of the poor and needy — since this sin represented their usual behavior more than any other. Besides, since all peoples act righteously towards their friends and their poor, there was none among all the nations who matched Sodom in cruelty.
Know that the judgment of Sodom was due to the superiority of the Land of Israel since Sodom is part of the inheritance of the Eternal,¹⁸¹II Samuel 20:19. and it does not suffer men of abominations. And just as it later vomited out a whole nation on account of their abominations,¹⁸²See Leviticus 18:25. so it now anticipated and saw that this entire people behaved worse than all nations towards Heaven and mankind. It thus laid waste heaven and earth for them, and the land was destroyed forever, never to be restored, since they became haughty on account of the goodness that was bestowed on them. The Holy One, blessed be He, thus made Sodom a token against the rebellious children,¹⁸³Numbers 17:25. that is, against the children of Israel who were destined to inherit it, even as He warned them: The whole land thereof is brimstone, and salt, and a burning… like the overthrow of Sodom and Gomorrah, Admah and Zeboiim, which the Eternal overthrew in His anger, and in His wrath.¹⁸⁴Deuteronomy 29:22. For there have been among nations those who were evil and exceedingly sinful, and yet He did not do to them as He did to Sodom. However it was all on account of the superiority of this land for there is the temple of the Eternal.¹⁸⁵Jeremiah 7:4. I plan to explain this in Seder Achrei Moth,¹⁸⁶Leviticus 18:24. if He Who taketh life and giveth life will sustain me in life.