Musar for Kiddushin 61:6

The two verses commencing with ויקומו, and ending with the words על קהל ה' by (16,3), lend themselves to two different interpretations. When Korach and Datan and Aviram spoke these words, they were criminal words. When the two hundred and fifty men spoke the same words, their intentions were honourable. In the case of Korach and Co. it means they elevated themselves, rose against Moses and Aaron. Targum Yonathan interprets: they spoke with חוצפה. Rashi says that they claimed there was no cause for Moses and Aaron to feel superior since the entire nation had heard G–d speak the first two of the Ten Commandments directly. Their evil intention was to deny Moses' standing as a prophet. They sought to prove that the whole nation qualified for the same spiritual level, and that anything over and beyond Moses had said in the name of G–d had really been his own invention. They argued that if all these other pronouncements had really emanated from G–d, G–d Himself would have communicated them to the people directly. It follows that Moses had also acted high--handedly when he appointed Aaron as High Priest. The appointment of Elitzafan as head of the Kehatites had been at Moses' own initiative. Even though Korach and Datan and Aviram respectively agreed in this particular denial of the truth, the latter's agreement was still not identical to that of Korach. Korach spoke out against the prophetic status of Moses and at the same time he also spoke out against G–d, suggesting that since G–d had only spoken the first two commandments, He had obviously only had His own honour and glory in mind. When Kidushin 31a described the nations of the world as approving of the Ten Commandments, according respect to G–d, such respect was based on G–d commanding us to honour our parents. Since Korach did not allow that the commandment to honour father and mother was of Divine origin, he obviously distorted G–d's intentions when revealing the first two commandments. We see that Korach only scoffed when he referred to what the people had heard from the mouth of G–d. Afterwards he proceeded to deny the prinicple as well as the details. Datan and Aviram, though denying basic truths, did not do so to the extent Korach had done. They only suspected Moses of having appointed Aaron, his sons, and Elitzafan without having been instructed by G–d to do so. They believed that if these appointments had been at the command of G–d, He would have told Israel about it, just as He had told them about His own position as Lord and Master of the Jewish people. Moreover, we have a principle אין ממנים פרנס על הציבור אלא מדעת הציבור, "one must not appoint an administrator for the community unless that community had approved of that appointment" (Berachot 55). At any rate, both of them made common cause with Korach, challenging Moses.