Yerushalmi Sanhedrin, 10a #1 (citing R. B'rachyah in the name of R. Chelbo: It incorporates even their names, which disappeared from all their storehouses and documents and rolled down the hole.

Yerushalmi Sanhedrin, 10a #2 (citing R. Eliezer: It incorporates even a needle that someone had borrowed from them rolled down the hole. ¹

R. Bachye (citing Eruvin 19a): It means ?they descended alive to the seventh (and bottom) level of Gehinom? ¹ (and this teaches us that one of the three entrances ² to Gehinom is in the desert - Eruvin). ³

R. Bachye (on Pasuk 35): Because it is the way of Hakadosh-Baruch-Hu to punish ?Midah ke?Neged Midah?. Consequently, since Korach ?the father of all egoists, in his attack against Hashem, sought to raise himself to a high position that was not his, Hashem sent him down - ?Midah k?Neged Midah?. ¹

Ramban and Seforno: Refer to 16:30:1:5 .

Sanhedrin 108a (according to R. Akiva): It means that they will not arise at Techi?as ha?Meisim. ¹

Ramban #1: It means that they disappeared before the eyes of the congregation; one moment they were standing there, the next moment they were gone, leaving no sign of where they had just been standing.

Ramban #2 (citing Ibn Ezra): It means that they perished together with their children, who should have replaced them.

Sanhedrin, 108a: It means that they also lost their portion in the world to come. ^{1 2}

Yerushalmi Sanhedrin, 10:4: The Torah is comparing them via a Gezeirah Shavah "Vayovdu" "Hayisi ke'Seh Oveid, Bakeish Avdecha!" - in Tehilim, 119:176 - to a lost article that is sought, ³ so too, will the congregation of Korach be sought - and will merit a portion in the world to come. ⁴