Korach: Chapter 1
"Now Korah..."

Rabbi Yitzchak tells us that if the children of Yisrael had followed the Torah they would not have been exiled, because whoever deals in the Torah has freedom from everything including death. The Torah is the power of the right, and whoever exchanges the left for the right is as if he destroys the world. Rabbi Yitzchak says that Aaron is right and the Levites are left, and that Korah wanted to exchange them in that he desired the priesthood; this is why he was punished. Korah had an evil tongue, he took bad counsel, he chased after something that was not his, and he turned to disagreement which brought conflict instead of peace. The Shabbat is the peace of the upper and lower grades, and by this peace the world endures; whoever creates dissension in this peace will be destroyed.