2 But who says it, and to whom says he it? What shall we say, brethren? Is it the flesh that says, “Praise thou the Lord, O my soul”? And can the flesh suggest good counsel to the soul? However much the flesh be conquered, and subjected as a servant to us through strength which the Lord imparts, that it serve us entirely as a bond slave, enough for us that it hinder us not....For the body, inasmuch as it is the body, is even beneath the soul; and every soul, however vile, is found more excellent than the most excellent body. And let not this seem to you to be wonderful, that even any vile and sinful soul is better than any great and most surpassing body. It is better, not in deserts, but in nature. The soul indeed is sinful, is stained with certain defilements of lusts; yet gold, though rusted, is better than the most polished lead. Let your mind then run over every part of creation, and you will see that what we are saying is not incredible, that a soul, however blameable, is yet more praiseworthy than a praiseworthy body. There are two things, a soul and a body. The soul I chide, the body I praise: the soul I chide, because it is sinful; the body I praise, because it is sound. Yet it is in its own kind that I praise the soul, and in its own kind that I blame the soul: and so in its own kind I praise the body, or blame it. If you ask me which is better, what I have blamed or what I have praised, wondrous is the answer you will receive....So you speak of the best horse and the worst man: yet you prefer the man you find fault with to the horse you praise. The nature of the soul is more excellent than the nature of the body: it surpasses it by far, it is a thing spiritual, incorporeal, akin to the substance of God. It is somewhat invisible, it rules the body, moves the limbs, guides the senses, prepares thoughts, puts forth actions, takes in images of countless things; who is there, in short, beloved brethren, who may suffice for the praises of the soul? And yet such is the grace given to it, that this man says, “Praise the Lord, O my soul.”...It is not the flesh that says it. Let the body be angel-like, still it is inferior to the soul, it cannot give advice to its superior. The flesh when duly obedient is the handmaid of the soul: the soul rules, the body obeys; the soul commands, the body performs; how then can the flesh give this advice to the soul? Is it then perchance the soul herself, who says to herself, and in a manner commands herself, and exhorts and asks herself? For through certain passions in one part of her nature she wavered; but in another part, which they call the reasonable mind, the wisdom whereby she thinks, clinging to God, and now sighing towards Him, she perceives that certain inferior parts of her are troubled by worldly emotions, and by a certain excitement of earthly desires, betake them to outward things, leaving God who is within; so she recalls herself from things outward to inward, from lower to higher, and says, “Praise the Lord, O my soul.”...The soul itself gives itself counsel from the light of God by the reasonable mind, whereby it conceives the wisdom fixed in the everlasting nature of its Author. It reads there of somewhat to be feared, to be praised, to be loved, to be longed for, and sought after: as yet it grasps it not, it comprehends it not; it is, as it were, dazzled with brightness; it has not strength to abide there. Therefore it gathers itself, as it were, into a sound state, and says, “Praise the Lord, O my soul.”...And then the soul, weighed down, as it were, and unable to stand up as is fitting, answers the mind, “I will praise the Lord in my life”. What is, “in my life”? Because now I am in my death. Therefore first encourage yourself, and say, “Praise the Lord, O my soul.” Your soul answers you, I do praise so far as I can, slightly, poorly, weakly. Wherefore? Because, “while we are in the body, we are absent from the Lord.”...
3. “In my life.” Now what has it? It might answer you, “My death.” Whence, “My death”? Because I am absent from the Lord. For if to cling to Him is life, to depart from Him is death. But what comforts you? Hope. Now you live in hope: in hope praise, in hope sing. Your death is from the sadness of this life, you live in hope of a future life. And how will you praise your Lord? “I will sing unto my God, as long as I have my being.” What sort of praise is this, “I will sing unto my God as long as I have being”? Behold, my brethren, what sort of being this will be; where there will be everlasting praise, there will be also everlasting being. Behold, now you have being: do you sing unto God as long as you have being? Behold, you were singing, and hast turned yourself away to some business, you sing no longer, yet you have being: you have being, yet you sing not. It may be also your desire turns you to somewhat; not only do you not sing, but thou even offendest His ears, yet you have being. What praise will that be, when you praise as long as you have being? But what means, “as long as I have being”? Will there be any time when he will not be? Nay, rather, that “long” will be everlasting, and therefore it will be truly “long.” For whatever has end in time, however prolonged it is, is yet not “long.”...
4. “Put not your trust in princes”. Brethren, here we receive a mighty task; it is a voice from heaven, from above it sounds to us. For now through some kind of weakness the soul of man, whenever it is in tribulation here, despairs of God, and chooses to rely on man. Let it be said to one when set in some affliction, “There is a great man, by whom you may be set free;” he smiles, he rejoices, he is lifted up. But if it is said to him, “God frees you,” he is chilled, so to speak, by despair. The aid of a mortal is promised, and you rejoice, the aid of the Immortal is promised, and are you sad? It is promised you that you shall be freed by one who needs to be freed with you, and you exult, as at some great aid: you are promised that Liberator, who needs none to free Him, and you despair, as though it were but a fable. Woe to such thoughts: they wander far; truly there is sad and great death in them. Approach, begin to long, begin to seek and to know Him by whom you were made. For He will not leave His work, if He be not left by His work.
5....“His breath shall go forth, and he shall return to his earth: in that day shall all his thoughts perish”. Where is swelling? Where is pride? Where is boasting? But perhaps he will have passed to a good place, if indeed he have passed. For I know not whither he who spoke thus has passed. For he spoke in pride; and I know not whither such men pass, save that I look into another Psalm, and see that their passage is an evil one. “I beheld the wicked lifted up above the cedars of Libanus, and I passed by, and, lo, he was not; and I sought him, and his place was not found.” The good man, who passed by, and found not the wicked, reached a place where the wicked is not. Wherefore, brethren, let us all listen: brethren, beloved of God, let us all listen; in whatsoever tribulation, in whatsoever longing for the heavenly gift, “let us not trust in princes, nor in sons of men, in whom is no salvation.” All this is mortal, fleeting, perishable.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)