Or HaChaim on Numbers 17:20/אור החיים על במדבר י״ז:כ׳

1 והיה האיש אשר אבחר בו, "and it will be that the rod of the man whom I choose will bud." All the miracles G'd had performed with Korach had not sufficed to convince the people. Perhaps this was because the people thought that Korach's sin was that he challenged Moses so that G'd had had to defend the honour of His prophet, but that this did not prove that G'd was not willing to choose another tribe from which the High Priest would be chosen.