9 Do you desire that we should lead you down again to the earth, and point out the marvel? Do you see not this sea abounding with waves, and fierce winds; yet this sea, spacious, and large, and furious as it is, is walled in with a feeble sand! Mark also the wisdom of God, He permitted it not to be at rest, nor tranquil, lest you should suppose its good order to be of mere natural regulation; but remaining within its limits, it lifts up its voice, and is in tumult, and roars aloud, and raises its waves to a prodigious height.
But when it comes to the shores, and beholds the sand, it breaks up, and returns back again within itself; teaching you, by both these things, that it is not the work of nature that it remains within its boundaries, but the work of Him whose power restrains it! For this cause accordingly He has made the wall feeble; and has not encompassed these shores with wood, or stone, or mountains, lest you should impute the regulation of the elements to such things. And, therefore, God Himself, upbraiding the Jews with this very circumstance, said, “Fear ye not Me, which have placed the sand for the bound of the sea that it cannot pass it.” But the marvellous thing is not this only, that He has made a great and admirable world; and that He has compacted it in a way above the usual course of nature; but that He has also constituted it out of opposite things; such as hot and cold, dry and moist, fire and water, earth and air, and that these contrary elements, of which this whole universe consists, though continually at strife one with another, are not consumed of one another.
The fire has not overrun and burnt up all things; the water has not overflowed and drowned the whole earth. With respect to our bodies, however, these effects really take place; and upon the increase of the bile, fever is generated; and the whole animal frame sustains an injury; and when there is a superabundance of phlegm, many diseases are produced which destroy the animal. But in the case of the universe, nothing of this kind happens; but each thing remains held as it were by a kind of bridle and band; preserving, by the will of the Creator, its own boundaries; and their strife becomes a source of peace to the whole.
Are not these things evident even to a blind man? And are not even the simple easily able to comprehend, that they were made, and are upheld, by some Providence? For who is so silly and senseless, that beholding such a mass of substances, such beauty, such combination, the continual strife of such vast elements, their opposition, and yet durability, would not reason with himself and say, If there were not some Providence to uphold the mass of these bodies, not permitting the universe to fall to pieces, it could not remain; it could not have been lasting.
So perfect is the order of the seasons, such the harmony of the day and night, so many the kinds of brute animals, and plants, and seeds, and herbs, that preserve their course, and yet, to the present day, none has ever fallen into decay or sudden dissolution.
Source: Homilies on the Statues (New Advent)