Charles Ellicott Commentary Psalms 106:17

"The earth opened and swallowed up Dathan, And covered the company of Abiram." — Psalms 106:17 (ASV)

The omission of Korah is in keeping with the historical accounts, which indicate a difference both in the attitude of Korah and his family from that of Dathan and Abiram, and also a difference of fate. (Compare to Numbers 16:23 and following; Deuteronomy 11:6; Numbers 26:10.)