waters thereof roar. Figure of speech Hypocatastasis (App-6), implying the raging of the Assyrian host without.
roar. Same word as "raged" (Psalms 46:6).
Selah. Connecting the roaring of the waters without with the silent flowing river in the rock-cut channel beneath Zion, and contrasting the boastings of the enemy with the secret purposes of God. No refrain "dropped out" here, as some suggest. See the Structure above, and App-68.