John Gill Commentary Psalms 114:6

"Ye mountains, that ye skip like rams; Ye little hills, like lambs?" — Psalms 114:6 (ASV)

You mountains, that you skipped like rams
Not for joy, but fear; what caused these trembling motions, these violent agitations, and quakings, and movings to and fro like the skipping of rams?

And you little hills, like lambs ?
what was it that disturbed you, and put you into a panic, that you skipped like frightened lambs? These questions are put, by a beautiful and poetical figure, to inanimate creatures; the Red sea, the river of Jordan, the mountains of Sinai and Horeb, and the hills about them; to which an answer is turned in the next verse.