John Calvin Commentary Psalms 114:3

"The sea saw it, and fled; The Jordan was driven back." — Psalms 114:3 (ASV)

The sea saw, and fled: He does not recount in order all the miracles that were performed at that time, but briefly alludes to the sea, which, though a lifeless and senseless element, is still struck with terror by the power of God. Jordan did the same, and the very mountains shook.

It is in a poetical style that the Psalmist describes the receding of the sea and of the Jordan. The description, however, does not exceed the facts of the case. The sea, by rendering such obedience to its Creator, sanctified his name; and Jordan, by its submission, honored his power; and the mountains, by their quaking, proclaimed how they were overawed by the presence of his dreadful majesty.

By these examples, it is not intended to celebrate God’s power more than the fatherly care and desire which he shows for the preservation of the Church; and accordingly, Israel is quite properly distinguished from the sea, the Jordan, and the mountains—as there is a very marked difference between the chosen people and the insensate elements.