1. Although the arrangement of the Psalms, which seems to me to contain the secret of a mighty mystery, hath not yet been revealed unto me, yet, by the fact that they in all amount to one hundred and fifty, they suggest somewhat even to us, who have not as yet pierced with the eye of our mind the depth of their entire arrangement, whereon we may without being over-bold, so far as God giveth, be able to speak. Firstly, the number fifteen, whereof it is a multiple this number fifteen, I say, signifieth the agreement of the two Testaments. For in the former is observed the Sabbath, which signifieth rest; in the latter the Lord's Day, which signifieth resurrection. The Sabbath is the seventh day, but the Lord's Day, coming after the seventh, must needs be the eighth, and is also to be reckoned the first. For it is called the first day of the week, and so from it are reckoned the second, third, fourth, and so on to the seventh day of the week, which is the Sabbath. But from Lord's Day to Lord's Day is eight days, wherein is declared the revelation of the New Testament, which in the Old was as it were veiled under earthly promises. Further, seven and eight make fifteen. Of the same number too are the Psalms which are called "of the steps," because that was the number of the steps of the Temple. Further too, the number fifty in itself also containeth a great mystery. For it consisteth of a week of weeks, with the addition of one as an eighth to complete the number of fifty. For seven times seven make forty-nine, whereto one is added to make fifty. And this number fifty is of so great meaning, that it was after the completion of that number of days from the Lord's Resurrection, that, on the fiftieth day exactly, the Holy Spirit came upon those who were gathered together in Christ. And this Holy Spirit is in Scripture especially spoken of by the number seven, whether in Isaiah or in the Apocalypse, where the seven Spirits of God are most directly mentioned, on account of the sevenfold operation of one and the self-same Spirit. And this sevenfold operation is mentioned in Isaiah. ...Hence also the Holy Spirit is spoken of under the number seven. But this period of fifty the Lord divided into forty and ten: for on the fortieth day after His Resurrection He ascended into heaven, and then after ten days were completed He sent the Holy Spirit: under the number forty setting forth to us the period of temporal sojourn in this world. For the number four prevaileth in forty; and the world and the year have each four parts; and by the addition of the number ten, as a sort of reward added for the fulfilment of the law in good works, eternity itself is figured. This fifty the number one hundred and fifty containeth three times, as though it were multiplied by the Trinity. Wherefore for this reason too we make out that this number of the Psalm is not unsuitable.
2. Now in that some have believed that the Balms are divided into five books, they have been led by the fact, that so often at the end of Psalms are the words, "so be it, so be it." But when I endeavoured to make out the principle of this division, I was not able; for neither are the five parts equal one to another, neither in quantity of contents, nor yet even in number of Psalms, so as for each to contain thirty. And if each book end with, "so be it, so be it," we may reasonably ask, why the fifth and last book hath not the same conclusion. We however, following the authority of canonical Scripture, where it is said, "For it is written in the book of Psalms," know that there is but one book of Psalms. And I see indeed how this can be true, and yet the other be true also, without contravening it. For it may be that there was some custom in Hebrew literature, whereby that is called one book which yet consists of more than one, just as of many churches one church consisteth, and of many heavens one heaven, ...and one land of many lands. For it is our everyday habit to say, "the globe of the earth," and "the globe of the lands." And when it is said, "It is written in the book of Psalms," though the customary way of speaking is such that he seem to have wished to suggest that there is but one book, yet to this it may be answered, that the words mean "in a book of the Psalms," that is, "in any one of those five books." And this is in common language so unprecedented, or at least so rare, that we are only convinced that the twelve Prophets made one book, because we read in like manner, "As it is written in the book of the Prophets." There are some too who call all the canonical Scriptures together one book, because they agree in a very wondrous and divine unity. ...
3. Whichever then of these is understood, this book, in its parts of fifty Psalms each, gives an answer important and very worthy of consideration. For it seems to me not without significance, that the fiftieth is of penitence, the hundredth of mercy and judgment, the hundred and fiftieth of the praise of God in His saints. For thus do we advance to an everlasting life of happiness, first by condemning our own sins, then by living aright, that, having condemned our ill life, and lived a good life, we may attain to everlasting life. Our predestination is not wrought in ourselves, but in secret with Him, in His foreknowledge. But we are called by the preaching of repentance. We are justified in the calling of mercy and fear of judgment. He feareth not judgment, who hath previously attained salvation. Being called, we renounce the devil by repentance, that we may not continue under his yoke: being justified, we are healed by mercy, that we may not fear judgment: being glorified, we pass into everlasting life, where we praise God without end. ...The verse wherewith this Psalm concludeth is the voice of life everlasting.
4. "Praise the Lord in His saints," that is, in those whom He hath glorified: "praise Him in the firmament of His power" (ver. 1). "Praise Him in His deeds of strength;" or, as others have explained it, "in His deeds of power: praise Him according to the multitude of His greatness" (ver. 2). All these His saints are; as the Apostle saith, "But we may be the righteousness of God in Him." If then they be the righteousness of God, which He hath wrought in them, why are they not also the strength of Christ which He hath wrought in them, that they should rise again from the dead? For in Christ's resurrection, "strength" is especially set forth to us, for in His Passion was weakness, as the Apostle saith. And well doth it say, "the firmament of His power." For it is the "firmament of His power" that He "dieth no more, death hath no more dominion over Him." Why should not they also be called "the works of" God's "strength," which He hath done in them: yea rather, they themselves are the works of His strength; just as it is said, "We are the righteousness of God in Him." For what more powerful than that He should reign for ever, with all His enemies put under His feet? Why should not they also be "the multitude of His greatness"? not that whereby He is great, but whereby He hath made them great, many as they are, that is, thousands of thousands. Just as righteousness too is understood in two ways, that whereby He is righteous, and that which He worketh in us, so as to make us His righteousness. These same saints are signified by all the musical instruments in succession, to praise God in. For what the Psalmist began with, saying, "Praise the Lord in His saints," that he carrieth out, signifying in various ways these same saints of His.
5. "Praise Him in the sound of the trumpet" (ver. 3): on account of the surpassing clearness of note of their praise. "Praise Him in the psaltery and harp." The psaltery praiseth God from things above, the harp praiseth God from things below; I mean, from things in heaven, and things in earth, as He who made heaven and earth. We have already in another Psalm, explained that the psaltery hath that board, whereon the series of strings rests that it may give a better sound, above, whereas the harp has it below. "Praise Him in the timbrel and choir" (ver. 4). The "timbrel" praiseth God when the flesh is now changed, so that there is in it no weakness of earthly corruption. For the timbrel is made of leather dried and strengthened. The "choir" praiseth God when society made peaceful praiseth Him. "Praise Him on the strings and organ." Both psaltery and harp, which have been mentioned above, have strings. But "organ" is a general name for all instruments of music, although usage has now obtained that those are specially called organ which are inflated with bellows: but I do not think that this kind is meant here. For since organ is a Greek word, applied generally, as I have said, to all musical instruments, this instrument, to which bellows are applied, is called by the Greeks by another name: but it being called organ is rather a Latin and conversational usage. When then he saith, "on the strings and organ," he seemeth to me to have intended to signify some instrument which hath strings. For it is not psalteries and harps only that have strings: but, because in the psaltery, and harp, on account of the sound from things below and things above, somewhat has been found which can be understood after this distinction, he hath suggested to us to seek some other meaning in the strings themselves: for they too are flesh, but flesh now set free from corruption. And to those, it may be, he added the organ, to signify that they sound not each separately, but sound together in most harmonious diversity, just as they are arranged in a musical instrument. For even then the saints of God will have their differences, accordant, not discordant, that is, agreeing, not disagreeing, just as sweetest harmony arises from sounds differing indeed, but not opposed to one another.
6. "Praise Him on the well-sounding cymbals, praise Him on cymbals of jubilation" (ver. 5). Cymbals touch one another in order to sound, and therefore are by some compared to our lips. But I think it better to understand that God is in a manner praised on the cymbal, when each is honoured by his neighbour, not by himself, and then honouring one another, they give praise to God. But lest any should under stand such cymbals as sound without life, therefore I think he added, "on cymbals of jubilation." For "jubilation" that is, unspeakable praise, proceedeth not, save from life. Nor do I think that I should pass over what musicians say, that there are three kinds of sounds,by voice, by breath, by striking: by voice, uttered by throat and windpipe, when man singeth without any instrument; by breath, as by pipe, or anything of that sort: by striking, as by harp, or anything of that kind. None then of these kinds is omitted here: for there is voice in the choir, breath in the trumpet, striking in the harp, representing mind, spirit, body, but by similitudes, not in the proper sense of the words. When then he proposed, "Praise God in His saints," to whom said he this, save to themselves? And in whom are they to praise God, save in themselves? For ye, saith he, are "His saints;" ye are "His strength," but that which He wrought in you; ye are "His mighty works, an d the multitude of His greatness," which He hath wrought and set forth in you. Ye are "trumpet, psaltery, harp, timbrel, choir, strings, and organ, cymbals of jubilation sounding well," because sounding in harmony. All these are ye: let nought that is vile, nought that is transitory, nought that is ludicrous, be here thought of. And since to savour of the flesh is death, "let every spirit praise the Lord" (ver. 6).