John Gill Commentary Psalms 124:4

"Then the waters had overwhelmed us, The stream had gone over our soul;" — Psalms 124:4 (ASV)

Then the waters had overwhelmed us
People, comparable to waters for their multitude, Strength, force, and impetuosity; which bear down all before them, and against which there is no standing; which, like the waters of the flood, overflow and destroy all they pass over.

These are the floods of ungodly men, which are very destructive and terrible; see (Revelation 17:15) (Isaiah 8:7Isaiah 8:8) (Psalms 18:4) ;

together with all those reproaches, afflictions, and persecutions, which come along with them; which the presence of God only can bear up his people under, and carry them through, (Song of Solomon 8:7) (Psalms 69:1Psalms 69:2) (Isaiah 43:2) ;

the stream had gone over our soul ;
and so deprived them of life; the whole force of the enemy; which, like a stream, flows in with great strength and rapidity, when a breach is made and spreads itself,

Arama interprets it of the stream of the Egyptians, and restrains it to them, their armies and forces; but it rather designs others, and the enemies of God's people in general, which threaten their ruin, even their very souls and lives:

it may be applied to the stream of corruptions, the flood of temptation and flow of persecutions, such as the flood the dragon cast out of his mouth after the woman; which, were it not for divine grace and assistance, would destroy the saints, who have no might against this great force, (2 Chronicles 20:12) (Isaiah 59:19) (Revelation 12:16) .