Mussar sobre Números 16:33

We also find in Arachin 15b: R. Yehoshua b. Levi said: "If one speaks lashon hara, his sins mount unto the heavens, viz. (Psalms 73:9): "They set their mouths in the heavens and [(i.e., when)] their tongues run on the earth." And it [lashon hara] is over and against the three grave sins, as mentioned above in Chapter IV. And just as it is over and against, so is its punishment, as we find in Yerushalmi Peah 1:5 and in Semag, that for four things punishment is exacted of a person in this world, and the principle is left for him for the world to come. They are: idolatry, illicit relations, and blood-spilling, and lashon hara over and against all. And, likewise, we have written above in Chapter VI in the name of Sefer Hakaneh that for the sin of lashon hara he is smitten with poverty. And we find also in Tanna d'bei Eliyahu 16: "Those who smite in secret 'i.e., speakers of lashon hara] and desecrators of the Name in the open and those who cheapen their friends with words, and those who instigate quarrels will, in the end, be like Korach [and his congregation] of whom it is written (Bamidbar 16:33): "And the earth covered them up."

This is the language of the Midrash Rabbah on Korach: "R. Berechiah said: 'How severe is machloketh! For the upper beth-din punishes only from twenty years and above, and the lower beth-din from thirteen and above; but in the machloketh of Korach, one-year-old infants were swallowed up in the depths of Sheol, as it is written (Numbers 16:27): '…and their wives and their sons and their infants… (Ibid. 33): …went down — they and all that was theirs, alive into Sheol.'"

When the Talmud in Sanhedrin 108, debates whether Korach and family will be resurrected when the time comes, the expression עדת קרח used there does not include these two hundred and fifty men. They will certainly qualify for resurrection, seeing theirs had been a noble intention. We can deduce this also from the wording in the Mishnah there which reads: עדת קרח אינה עתידה לעלות, which is proven from the verse: ותכס עליהם הארץ, "the earth covered them," an expression of finality (which clearly refers only to those who were swallowed by the earth).