“And Korach, the son of Yitzhar the son of Kehos the son of Levi, separated himself, and Dasan and Aviram the sons of Eliav, and On the son of Peles, the sons of Reuven.” 16:1
The son of Yitzhar, the son of Kehos, the son of Levi - But Scripture does not mention, "the son of Yaakov," since Yaakov implored Hashem for compassion that his name be omitted from their dispute, as it is said, ‘let my name not be identified with their assembly.’” – Rashi
It is no secret that Yaakov was the father of Levi. What then was accomplished by omitting mention of his name? Indeed, what Yaakov sought to avoid with his plea to be omitted was not posthumous shame. Rather, he hoped to impress upon Levi that his actions were inconsistent with Yaakov’s philosophy. Although his words may not have their intended effect on Levi’s descendent, Korach, he was no longer considered culpable, because early on, he had lodged his protest. By omitting his name from the list of Korach’s ancestors, the Torah is teaching us that even an unheeded protest is not wasted. Korach would go down in history as a villain, but Yaakov, by virtue of his protest, would bear no guilt in the matter.