After Korach spits out his rebellious barrage against Moshe and Aharon, the pasuk says (16:4) ‘and Moshe heard.’ What do these words mean; of course Moshe heard (he was not deaf) – what is the pasuk telling us? The idea is that Moshe looked deeper and understood where Korach’s claim was really coming from. Korach hid behind the claim of ‘the people do not need any leaders’ to charge his way to the leadership himself. Moshe understood exactly what Korach wanted and looked beyond the mere words that came out of Korach’s mouth. Moshe understood that (as the gemarra says) Korach’s argument was borne out of his haughtiness and lust for honour. This is why Moshe responded ‘in the morning HaShem will make known His chosen one’ – for Moshe knew that Korach really wanted to be the leader himself. This was a real act of hearing.