“Koraḥ assembled…against them” (Numbers 16:19) – He said to them: ‘“The entire congregation, all of them are holy” (Numbers 16:3), and all of them heard at Sinai: “I am the Lord your God” (Exodus 20:2), “and why do you elevate yourselves over the assembly of the Lord?” (Numbers 16:3). Had you heard it alone, and they had not heard, you could say it, but now, all of them heard. Why do you elevate yourselves?’
Moses was immediately shaken due to the dispute, because this was already their fourth wrongdoing. This is analogous to a king’s son who wronged his father. His dear friend placated him [the king] once, twice, three times. When he committed a fourth wrongdoing, the hands of the king’s dear friend were rendered powerless.
He said: ‘How many times can I impose upon the king?’ So it was with Moses. They sinned with the calf – “Moses prayed” (Exodus 32:11). “The people were as complainers” (Numbers 11:1) – “Moses prayed” (Numbers 11:2).
Regarding the spies – “Moses said: Egypt will hear…” (Numbers 14:13). Regarding Koraḥ’s dispute, he said: ‘How much can I impose upon the Omnipresent?’ That is why: “Moses heard and he fell on his face” (Numbers 16:4).