Koraḥ Disentangled

Koraḥ the son of Yitzhar, the son of Kehos, the son of Levi took [himself to one side] along with Dasan and Aviram, the sons of Eliav, and On the son of Peles, descendants of Reuven. Num. 16:1 There is a curious aspect to the story of Koraḥ’s rebellion. We can understand why Koraḥ (or Korach), being of the tribe of Levi, may have had a claim to the priesthood thus causing a rebellion against Mosheh and Aaron HaKohen, the High Priest.  The Torah tells us, however, that some Reubenites, that is, members of the tribe of Reuven, got entangled with the followers of Koraḥ in this rebellion as well.  But what did they have to do with it?  Not being descendants of Levi, they surely had no claim on the priesthood.  Why [...]