“And Korach undertook (literally, took) … and began a rebellion against Moses”
Abel had in him 37 sparks of goodness (הבל=5+2+30) and 308 bad sparks. Moses, who was a reincarnation of Abel, corrected all of Abel's sparks. The 308 bad sparks that were initially connected to Abel, are the secret meaning of the reincarnation of Korach, the gematria of whose name is also 308:
The hint that Moses corrected all of Abel's sparks is in the phrase “and his mother saw that the boy was good,” and in addition the value of Moses' name 345 is 37 (Abel) plus 308 (Korach).
Thus the essence of Korach's soul also comes from Abel. However, at the beginning of the events described in this Torah portion, the bad part of the soul of Cain connected itself to Korach, and this is the meaning of “and Korach took” on which the Sages commented that Korach took, or acquired, a bad purchase for himself. At first, Korach realized that although he comes from the bad sparks of Abel, he is still subjugated to Moses. However, when the soul of Cain connected to him, he decided that he does not have to be subservient anymore, and started a rebellion, repeating the conflict between Cain and Abel. As a result, Korach was removed from the world.
Art: Pietro Novelli - Cain and Abel