And Korach took [a bold step]…together with Datan and Aviram...and Ohn, the son of Pelet (Num. 16:1)
The Torah criticizes Datan and Aviram more than any other participants in Korach's rebellion as they mixed into a controversy that was none of their business. They weren't firstborn sons who might have resented having the priesthood taken away from them, nor were they even from the tribe of Levi. The priesthood was none of their concern.
(Machane Belula)
And Korach took (Num. 16:1)
Although it is customary for preachers to delve into the particular Torah reading of the week to find material for their lectures, drawing lessons from the portion of Korach is always appropriate, for unfortunately, controversy runs rampant and is not limited to one week a year.
(Daat Chachamim)
Korach, the son of Yitzhar, the son of Kehot, the son of Levi (Bamidbar 38:1)
A distinguished lineage is meaningful only when it brings a person to feel humbled in the face of his illustrious ancestors. Unfortunately, it sometimes has the opposite effect, resulting in baseless pride and arrogance. Korach is a prime example of the latter; too much self-esteem allowed him to rebel against Moses.
(Rabbi Naftali of Ropshitz)
And Moses sent to call Datan and Aviram (Num. 16:12)
It states in the Talmud (Sanhedrin 106): "From this we learn that one should not 'hold on' to controversy." Even if several attempts to make peace have been made without success, it is forbidden to throw up one's hands and assume that nothing more can be done. Rather, one must continue one's efforts until peace is attained. Thus despite the fact that Moses had already spoken to Datan and Aviram several times, he attempted one more time to dissuade them.
(Rabbi Yitzchak of Vorky)