The sea saw it - The word it is supplied, not very properly, by our translators. It would be more expressive to say, "The sea saw:" that is, The sea - (the Red Sea) - saw the mighty movement - the marshalled hosts - the moving masses - the cattle - the pursuing enemies - the commotion - the agitation - on its usually quiet shores. We are to conceive of the usual calmness of the desert - the waste and lonely solitudes on the banks of the Red Sea - and then all this suddenly broken in upon by vast hosts of men, women, children, and cattle, fleeing in consternation, followed by the embattled strength of Egypt - all rolling on tumultuously to the shore. No wonder that the sea is represented as astonished at this unusual spectacle, and as fleeing in dismay.

And fled - As if affrighted at the approach of such an host, coming so suddenly upon its shores.

Jordan was driven back - Referring to the dividing of the waters of the Jordan when the children of Israel passed over to the promised land. Joshua 3:13-17. They also seemed astonished at the approach of the Hebrews, and retired to make a way for them to pass over.

Psalm 114:3 Parallel Commentaries

Effectual Calling
THE second qualification of the persons to whom this privilege in the text belongs, is, They are the called of God. All things work for good "to them who are called." Though this word called is placed in order after loving of God, yet in nature it goes before it. Love is first named, but not first wrought; we must be called of God, before we can love God. Calling is made (Rom. viii. 30) the middle link of the golden chain of salvation. It is placed between predestination and glorification; and if …
Thomas Watson—A Divine Cordial