St. Augustin on the Psalms.
1. "Give thanks unto the Lord, for He is good, for His mercy endureth for ever" (ver.1). This Psalm contains the praise of God, and all its verses finish in the same way. Wherefore although many things are related here in praise of God, yet His mercy is most commended;  for without this plain commendation, he, whom the Holy Spirit used to utter this Psalm, would have no verse be ended. Although after the judgment, by which at the end of the world the quick and the dead must be judged, the just being sent into life eternal, the unjust into everlasting fire,  there will not afterwards be those, whom God will have mercy on, yet rightly may His future mercy be understood to be for ever, which He bestows on His saints and faithful ones, not because they will be miserable for ever, and therefore will need His mercy for ever, but because that very blessedness, which He mercifully bestows on the miserable, that they cease to be miserable, and begin to be happy, will have no end, and therefore "His mercy is for ever." For that we shall be just from being unjust, whole from being unsound, alive from being dead, immortal from being mortal, happy from being wretched, is of His mercy. But this that we shall be, will be for ever, and therefore "His mercy is for ever." Wherefore, "give thanks to the Lord;" that is, praise the Lord by giving thanks, "for He is good:" nor is it any temporal good you will gain from this confession, for, "His mercy endureth for ever;" that is, the benefit which He bestows mercifully upon you, is for ever. 
2. Then follows, "Give thanks to the God of gods, for His mercy endureth for ever" (ver.2). "Give thanks to the Lord of lords, for His mercy endureth for ever" (ver.3). We may well enquire, Who are these gods and lords, of whom He who is the true God is God and Lord? And we find written in another Psalm, that even men are called gods.  The Lord even takes note of this testimony in the Gospel, saying, "Is it not written in your Law, I have said, Ye are gods?"  ...It is not therefore because they are all good, but because "the word of God came to them," that they were called gods. For were it because they are all good, He would not thus distinguish between them. He saith, "He judgeth between the gods." Then follows, "How long do ye judge iniquity!"  and the rest, which He says certainly not to all, but to some, because He saith it in distinguishing, and yet He distinguisheth between the gods.
3. But it is asked, If men are called gods to whom the word of the Lord came, are the Angels to be called gods, when the greatest reward which is promised to just and holy men is the being equal to Angels? In the Scriptures I know not whether it can, at least easily, be found, that the Angels are openly called gods; but when it had been said of the Lord God, "He is terrible, above all gods," he adds, as by way of exposition why he says this, "for the gods of the heathen are devils,"  that we might understand what had been expressed in the Hebrew, "the gods of the Gentiles are idols," meaning rather the devils which dwell in the idols.  For as regards images, which in Greek are called idols, a name we now use in Latin, they have eyes and see not, and all the other things which are said of them, because they are utterly without sense; wherefore they cannot be frightened, for nothing which has no sense can be frightened. How then can it be said of the Lord, "He is terrible above all gods, because the gods of the Gentiles are idols," if the devils which may be terrified are not understood to be in these images. Whence also the Apostle says, "We know that an idol is nothing."  This refers to its earthy senseless material. But that no one may think, that there is no living and sentient nature, which delights in the Gentile sacrifices, he adds, "But what the Gentiles sacrifice, they sacrifice to devils, and not to God: I would not have you partaken with devils."  If therefore we never find in the divine words that the holy Angels are called gods, I think the best reason is, that men may not be induced by the name to pay that ministry and service of religion (which in Greek is called leitourgia or latria) to the holy Angels, which neither would they have paid by man at all, save to that God, who is the God of themselves and men.  Hence they are much more correctly called Angels, which in Latin is Nuntii, that by the name of their function, not their substance, we may plainly understand that they would have us worship the God, whom they announce. The whole then of that question the Apostle has briefly expounded, when he says, "For though there be who are called gods, whether in heaven or in earth, as there are gods many and lords many; yet we have one God the Father, from whom are all, and we in Him; and one Lord Jesus Christ, by whom are all things, and we by Him." 
4. Let us therefore "give thanks to the God of gods, and the Lord of lords, for His mercy," etc. "Who alone did wonderful things" (ver.4). As at the last part of every verse, it is written, "For His mercy endureth for ever," so we must understand at the beginning of each, though it be not written, "Give thanks." Which indeed in the Greek is very plain. It would be so in Latin, if our translators had been able to make use of that expression. Which indeed they could have done in this verse, if they had said, "To Him who doeth  wonderful things." For where we have, "who did wonderful things," the Greek has to poiesanti, where we must necessarily understand, "give thanks." And I would they had added the pronoun, and said to Him, "who did," or to Him "who doeth," or to Him "who made sure;" because then one might easily understand, "let us give thanks." For now it is so obscurely rendered, that he who either knows not or cares not to examine a Greek manuscript may think, "who made the heavens, who made sure the earth, who made the luminaries, for His mercy endureth for ever,"  has been so said, because He did these things for this reason, "because His mercy endureth for ever:" whereas they, whom He has freed from misery, belong to His Mercy: but not that we should believe that He makes sky, earth, and luminaries, of His Mercy; since they are marks of His Goodness, who created all things very good.  For He created all things, that they might have their being;  but it is the work of His Mercy, to cleanse us from our sins, and deliver us from everlasting misery. And so the Psalm thus addresses us, "Give thanks unto the God of gods, give thanks unto the Lord of lords." Give thanks to Him, "who alone doeth great wonders;" give thanks to Him, "who by His wisdom made the heavens;" give thanks to Him, "who stretched out the earth above the waters;" give thanks to Him, "who alone made great lights." But why we are to praise, he setteth down at the end of all the verses, "for His mercy endureth for ever."
5. But what meaneth, "who alone doeth great wonders"? Is it because many wonderful things He hath done by means of angels and men? Some wonderful things there are which God doeth alone, and these he enumerates, saying, "who by His wisdom made the heavens" (ver.5), "who stretched out the earth above the waters" (ver.6), "who alone made great lights" (ver.7). For this reason did he add "alone" in this verse also, because the other wonders which he is about to tell of, God did by means of man. For having said, "who alone made great lights," he goes on to explain what these are, "the sun to rule the day" (ver.8), "the moon and stars to govern the night" (ver.9); then he begins to tell the wonders which He did by means of angels and men: "who smote Egypt with their first-born" (ver.10), and the rest. The whole creation then God manifestly made, not by means of any creature, but "alone;" and of this creation he hath mentioned certain more eminent parts, that they might make us think on the whole; the heavens we can understand,  and the earth we see. And as there are visible heavens too, by mentioning the lights in them, he has bid us look on the whole body of the heavens as made by Him.
6. However, whether by what he saith, "who made the heavens in understanding," or, as others have rendered it, "in intelligence," he meant to signify, the heavens we can understand, or that He in His understanding or intelligence, that is, in His wisdom made the heavens (as it is elsewhere written, "in wisdom hast Thou made them all"  ), implying thereby the only-begotten Word, may be a question. But if it be so, that we are to understand that "God by His wisdom made the heavens," why saith He this only of the heavens, whereas God made all things by the same wisdom? It is that it needed only to be expressed there, so that in the rest it might be understood without being written. How then could it be "alone," if "in understanding" or "in intelligence" means "by His wisdom," that is, by the only-begotten Word? Is it that, inasmuch as the Trinity is not three Gods, but one God, he states that God made these things alone, because He made not creation by means of any creature?
7. But what is, "who laid out the earth above the waters"? For it is a difficult question, because the earth seemeth to be the heavier, so that it should be believed not so much to be borne on the waters, as to bear the waters. And that we may not seem contentiously to maintain our Scriptures against those who think that they have discovered these matters on sure principles, we have a second interpretation to give, that the earth which is inhabited by men, and contains the living creatures of the earth, is "laid out above the waters" because it stands out above the waters which surround it. For when we speak of a city on the sea being built "above the waters," it is not meant that the sea is under it in the same way as the waters are under the chambers of caverns, or under ships sailing over them; but it is said to be "above" the sea, because it stands up above the sea below it.
8. But if these words further signify something else which more closely concerns us, God "by His wisdom made the heavens," that is, His saints, spiritual men, to whom He has given not only to believe, but also to understand things divine; those who cannot yet attain to this, and only hold their faith firmly, as being beneath the heavens, are figured by the name of earth. And because they abide with unshaken belief upon the baptism they have received, therefore it is said, "He laid out the earth above the waters." Further, since it is written of our Lord Jesus Christ, that "in Him are hid all the treasures of wisdom and knowledge,"  and that these two, wisdom and knowledge, differ somewhat from one another is testified by other utterances of Scripture, especially in the words of holy Job,  where both are in a manner defined; not unsuitably then do we understand wisdom to consist in the knowledge and love of That which ever is and abideth unchangeable, which is God. For where he saith, "piety  is wisdom," in Greek is theos?beia, and to express the whole of this in Latin, we may call it worship of God.  But to depart from evil, which he calls knowledge, what else is it but to walk cautiously and heedfully "in the midst of a crooked and perverse generation,"  in the night, as it were, of this world, that each one by keeping himself from iniquity may avoid being confounded with the darkness, distinguished by the light of his proper gift....
9. "Who brought out Israel from the midst of them" (ver.11). He brought out also His saints and faithful ones from the midst of the wicked. "With a mighty Hand and stretched-out Arm" (ver.12). What more powerful, what more out-stretched, than that of which is said "To whom is the Arm of the Lord revealed?"  "Who divided the Red Sea in two parts" (ver.13). He divided also in such wise, that the same baptism should be to some unto life, to others unto death. "And brought out Israel through the midst of it" (ver.14). So too He brings out His renewed people through the laver of regeneration. "And overthrew Pharaoh and his power in the Red Sea" (ver.15). He quickly destroyeth both the sin of His people and the guilt thereof by baptism. "Who led His people through the wilderness" (ver.16). Us too He leadeth through the drought and barrenness of this world, that we perish not therein. "Who smote great kings" (ver.17), "and slew famous kings" (ver.18). From us too He smites and slays the deadly powers of the devil. "Sehon king of the Amorites" (ver.19), an "useless shoot," or "fiery temptation," for so is Sehon interpreted: the king of "them who cause bitterness," for such is the meaning of Amorites. "And Og, the king of Basan" (ver.20). The "heaper-together," such is the meaning of Og, and, king of "confusion," which Basan signifies. For what else doth the devil heap together but confusion? "And gave away their land for an heritage" (ver.21), "even an heritage unto Israel His servant" (ver.22). For He giveth them, whom once the devil owned, for an heritage to the seed of Abraham, that is, Christ. "Who remembered us in our low estate" (ver.23), "and redeemed us from our enemies" (ver.24) by the Blood of His only-begotten Son. "Who giveth food to all flesh" (ver.25), that is, to the whole race of mankind, not Israelites only, but Gentiles too; and of this Food is said, "My Flesh is meat indeed." "Give thanks unto the God of Heaven" (ver.26). "Give thanks unto the Lord of lords" (ver.27). For what he here says, "the God of Heaven," I suppose that he meant to express in other words what He had before said, "the God of gods." For what there he subjoined, he has here also repeated. "Give thanks unto the Lord of lords." "But to us there is but one God," etc., "and one Lord Jesus Christ, by whom are all things, and we by Him;"  to whom we confess that "His mercy endureth for ever."
 Lat. CXXXV.  [He says: "I remember, in the hundred and sixth Psalm, which begins in the same way, because the manuscript which I read had not for ever,' but, for ages' (in sæculum), His mercy,' that I enquired what we had better understand. For, in the Greek language, it is written, eis ton aiona, which may be interpreted, for ages' and (in æternum) for ever.' But it would be tedious to renew the enquiries I made as best I could in that place. But in this Psalm the same manuscript has not for ages,' which most have, but, for ever His mercy.'"--C.]  Matthew 25:46.  [He adds: "The expression, for He is good,' in the Greek is ?gathos; not as in the hundred and sixth Psalm, for there "He is good,' in Greek is chrestos. And so some have expounded the former, Since He is sweet.' For ?gathos is not good anyhow, but good most excellently."--C.]  Psalm 82:1, vi. 7.  John 10:34.  Psalm 82:2.  Psalm 96:4 seq.  Simulacrum; heidolon.  1 Corinthians 8:4.  1 Corinthians 10:20.  [The Roman dogma makes a verbal distinction as to worship of angels and saints, to meet the case as our author puts it here. But the vulgar cannot so distinguish; and everywhere, practically, this latria is offered. See Pius IX., the bull Ineffabilis.--C.]  1 Corinthians 8:5, 6.  Facienti mirabilia.  Psalm 136:5.  Genesis 1:31.  Wisd. i. 14.  Intelligibiles coelos.  Psalm 104:24.  Colossians 2:3.  [Job 28:28.--C.]  Pietas, Vulg.  Dei cultus.  Philip. ii. 15.  Isaiah 53:1.  1 Corinthians 8:5, 6.
 [He says: "I remember, in the hundred and sixth Psalm, which begins in the same way, because the manuscript which I read had not for ever,' but, for ages' (in sæculum), His mercy,' that I enquired what we had better understand. For, in the Greek language, it is written, eis ton aiona, which may be interpreted, for ages' and (in æternum) for ever.' But it would be tedious to renew the enquiries I made as best I could in that place. But in this Psalm the same manuscript has not for ages,' which most have, but, for ever His mercy.'"--C.]
 Matthew 25:46.
 [He adds: "The expression, for He is good,' in the Greek is ?gathos; not as in the hundred and sixth Psalm, for there "He is good,' in Greek is chrestos. And so some have expounded the former, Since He is sweet.' For ?gathos is not good anyhow, but good most excellently."--C.]
 Psalm 82:1, vi. 7.
 John 10:34.
 Psalm 82:2.
 Psalm 96:4 seq.
 Simulacrum; heidolon.
 1 Corinthians 8:4.
 1 Corinthians 10:20.
 [The Roman dogma makes a verbal distinction as to worship of angels and saints, to meet the case as our author puts it here. But the vulgar cannot so distinguish; and everywhere, practically, this latria is offered. See Pius IX., the bull Ineffabilis.--C.]
 1 Corinthians 8:5, 6.
 Facienti mirabilia.
 Psalm 136:5.
 Genesis 1:31.
 Wisd. i. 14.
 Intelligibiles coelos.
 Psalm 104:24.
 Colossians 2:3.
 [Job 28:28.--C.]
 Pietas, Vulg.
 Dei cultus.
 Philip. ii. 15.
 Isaiah 53:1.
 1 Corinthians 8:5, 6.