Charles Ellicott Commentary Psalms 18:15

"Then the channels of waters appeared, And the foundations of the world were laid bare, At thy rebuke, O Jehovah, At the blast of the breath of thy nostrils." — Psalms 18:15 (ASV)

The channels. —The description of the storm ends with the fury of the wind and the effects of the tempest on the earth’s surface. Compare to Psalm 29:0, and Milton:—

“Either tropic now
Began thunder and both ends of heaven the clouds,
From many a horrid rift abortive poured
Fierce rain with lightning mixed, water with fire,
In ruin reconciled; nor slept the winds
Within their stony caves, but rushed abroad
From the four hinges of the world and fell
On the vexed wilderness.”

—Paradise Regained, Book IV, lines 409-416.

Here, to suit the poet’s purpose (see next verse), the rage of the tempest is made to spend itself on the water-floods. The “channels” are either torrent beds (Isaiah 8:7; Psalms 42:1; Job 6:15), or as in Samuel (where for “waters” the text has “sea”) the depths of ocean. (Compare to Jonah 2:5.)