earth opened: Num 16:2, Num 16:31-35, Num 16:38, Num 27:3; Exo 16:35; Psa 106:17-18
together: The Samaritan text does not intimate that Korah was swallowed up, but that he was burnt, as appears to have been the fact; and the Psalmist also (Psa 106:17), only mentions Dathan and Abiram as having been swallowed up. "And the earth swallowed them up, what time that company died; and the fire devoured Korah with the 250 men, who became a sign."
they became a sign: Num 16:38; 1Sa 2:34; Jer 29:22; Eze 14:8; 1Co 10:6-10; 2Pe 2:6; Jud 1:7