2 Nor is this the only thing that proves the dignity of the water. But there is also that which is more honourable than all— the fact that Christ, the Maker of all, came down as the rain, and was known as a spring, and diffused Himself as a river, and was baptized in the Jordan. For you have just heard how Jesus came to John, and was baptized by him in the Jordan. Oh things strange beyond compare! How should the boundless River that makes glad the city of God have been dipped in a little water!
The illimitable Spring that bears life to all men, and has no end, was covered by poor and temporary waters! He who is present everywhere, and absent nowhere— who is incomprehensible to angels and invisible to men— comes to the baptism according to His own good pleasure. When you hear these things, beloved, take them not as if spoken literally, but accept them as presented in a figure. Whence also the Lord was not unnoticed by the watery element in what He did in secret, in the kindness of His condescension to man.
“For the waters saw Him, and were afraid.” They wellnigh broke from their place, and burst away from their boundary. Hence the prophet, having this in his view many generations ago, puts the question, “What ails you, O sea, that you reddest; and you, Jordan, that you were driven back?” And they in reply said, We have seen the Creator of all things in the “form of a servant,” and being ignorant of the mystery of the economy, we were lashed with fear.
Source: Discourse on the Holy Theophany (New Advent)