Adam Clarke on Psalms 114:5

What ailed thee, O thou sea - The original is very abrupt; and the prosopopoeia, or personification very fine and expressive: -

What to thee, O sea, that thou fleddest away!

O Jordan, that thou didst roll back!

Ye mountains, that ye leaped like rams!

And ye hills, like the young of the fold!

After these very sublime interrogations, God appears; and the psalmist proceeds as if answering his own questions: -

At the appearance of the Lord, O earth, thou didst tremble;

At the appearance of the strong God of Jacob.

Converting the rock into a pool of waters;

The granite into water springs.

I know the present Hebrew text reads חולי chuli, "tremble thou," in the imperative; but almost all the Versions understood the word in past tense, and read as if the psalmist was answering his own questions, as stated in the translation above. "Tremble thou, O earth." As if he had said, Thou mayest well tremble, O earth, at the presence of the Lord, at the presence of the God of Jacob.