Then the channels of waters were seen. By "the channels of waters" seem to be meant the torrent-courses, so common in Palestine, especially on either side of Jordan, which convey into it the winter rains.
These "were seen," lit up by the "lightnings manifold," having previously been in darkness (see Psalms 18:9-11). At the same time, the foundations of the world were discovered. The earthquake (Psalms 18:7) still continuing, the earth gaped in places, and the glare of the lightning enabled the eye to penetrate deep into the solid globe—so deep that it seemed to reach the "foundations."
At thy rebuke, O Lord, at the blast of the breath of thy nostrils (comp. Psalms 18:7, "because he was wroth").