John Gill Commentary Psalms 124:3

"Then they had swallowed us up alive, When their wrath was kindled against us;" — Psalms 124:3 (ASV)

Then they had swallowed us up quick
Or "alive"; as the earth swallowed up Korah and his company; or as the fish swallowed up Jonah; or rather as ravenous beasts swallow their prey; to which the allusion is. The people of God are comparable to sheep and lambs, and such like innocent creatures: and the wicked to lions, tigers, wolves, bears, and such like beasts of prey that devour living creatures;

when their wrath was kindled against us ;
which is cruel and outrageous; there is no standing against it, nor before it; it is like a fierce flame of fire that burns furiously, and there is no stopping it; none but God can restrain it.