7 Let him then turn himself to things on earth too, since he has already spoken the praises of things in heaven. “Praise ye the Lord from the earth”. For wherewith began he before? “Praise ye the Lord from heaven:” and he went through things in heaven: now hear of things on earth. “Dragons and all abysses.” “Abysses” are depths of water: all the seas, and this atmosphere of clouds, pertain to the “abyss.” Where there are clouds, where there are storms, where there is rain, lightning, thunder, hail, snow, and all that God wills should be done above the earth, by this moist and misty atmosphere, all this he has mentioned under the name of earth, because it is very changeable and mortal; unless ye think that it rains from above the stars. All these things happen here, close to the earth. Sometimes even men are on the tops of mountains, and see the clouds beneath them, and often it rains: and all commotions which arise from the disturbance of the atmosphere, those who watch carefully see that they happen here, in this lower part of the universe....You see then what kind all these things are, changeable, troublous, fearful, corruptible: yet they have their place, they have their rank, they too in their degree fill up the beauty of the universe, and so they praise the Lord. He turns then to them, as though He would exhort them too, or us, that by considering them we may praise the Lord. “Dragons” live about the water, come out from caverns, fly through the air; the air is set in motion by them: “dragons” are a huge kind of living creatures, greater there are not upon the earth. Therefore with them he begins, “Dragons and all abysses.” There are caves of hidden waters, whence springs and streams come forth: some come forth to flow over the earth, some flow secretly beneath; and all this kind, all this damp nature of waters, together with the sea and this lower air, are called abyss, or “abysses,” where dragons live and praise God. What? Think we that the dragons form choirs, and praise God? Far from it. But do ye, when you consider the dragons, regard the Maker of the dragon, the Creator of the dragon: then, when you admire the dragons, and say, “Great is the Lord who made these,” then the dragons praise God by your voices.
8. “Fire, hail, snow, ice, wind of storms, which do His word”. Wherefore added he here, “which do His word”? Many foolish men, unable to contemplate and discern creation, in its several places and rank, performing its movements at the nod and commandment of God think that God does indeed rule all things above, but things below He despises, casts aside, abandons, so that He neither cares for them, nor guides, nor rules them; but that they are ruled by chance, how they can, as they can: and they are influenced by what they say sometimes to one another: e.g. “If it were God that gave rain, would He rain into the sea? What sort of providence,” they say, “is this? Getulia is thirsty, and it rains into the sea.” They think that they handle the matter cleverly. One should say to them, “Getulia does at all events thirst, thou dost not even thirst.” For good were it for you to say to God, “My soul has thirsted for You.” For he that thus argues is already satisfied; he thinks himself learned, he is not willing to learn, therefore he thirsts not. For if he thirsted, he would be willing to learn, and he would find that everything happens upon earth by God's Providence, and he would wonder at the arrangement of even the limbs of a flea. Attend, beloved. Who has arranged the limbs of a flea and a gnat, that they should have their proper order, life, motion? Consider one little creature, even the very smallest, whatever you will. If you consider the order of its limbs, and the animation of life whereby it moves; how does it shun death, love life, seek pleasures, avoid pain, exert various senses, vigorously use movements suitable to itself! Who gave its sting to the gnat, for it to suck blood with? How narrow is the pipe whereby it sucks! Who arranged all this? Who made all this? You are amazed at the smallest things; praise Him that is great. Hold then this, my brethren, let none shake you from your faith or from sound doctrine. He who made the Angel in heaven, the Same also made the worm upon earth: the Angel in heaven to dwell in heaven, the worm upon earth to abide on earth. He made not the Angel to creep in the mud, nor the worm to move in heaven. He has assigned dwellers to their different abodes; incorruption He assigned to incorruptible abodes, corruptible things to corruptible abodes. Observe the whole, praise the whole. He then who ordered the limbs of the worm, does He not govern the clouds? And wherefore rains He into the sea? As though there are not in the sea things which are nourished by rain; as though He made not fishes therein, as though He made not living creatures therein. Observe how the fishes run to sweet water. And wherefore, says he, does He give rain to the fishes, and sometimes gives not rain to me? That you may consider that you are in a desert region, and in a pilgrimage of life; that so this present life may grow bitter to you, that you may long for the life to come: or else that you may be scourged, punished, amended. And how well does He assign their properties to regions. Behold, since we have spoken of Getulia, He rains here nearly every year, and gives grain every year; here the grain cannot be kept, it soon rots, because it is given every year; there, because it is given seldom, both much is given, and it can be kept for long. But do you perchance think that God there deserts man, or that they do not there after their own manner of rejoicing both praise and glorify God? Take a Getulian from his country, and set him amid our pleasant trees; he will wish to flee away, and return to his bare Getulia. To all places then, regions, seasons, God has assigned and arranged what fits them. Who could unfold it? Yet they who have eyes see many things therein: when seen, they please; pleasing, they are praised; not they really, but He who made them; thus shall all things praise God.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)