Augustine of Hippo, The City of God XVII.14: Of David’s Concern in the Writing of the Psalms

In the progress of the city of God through the ages, therefore, David first reigned in the earthly Jerusalem as a shadow of that which was to come. Now David was a man skilled in songs, who dearly loved musical harmony, not with a vulgar delight, but with a believing disposition, and by it served his God, who is the true God, by the mystical representation of a great thing. For the rational and well-ordered concord of diverse sounds in harmonious variety suggests the compact unity of the well-ordered city. Then almost all his prophecy is in psalms, of which a hundred and fifty are contained in what we call the Book of Psalms, of which some will have it those only were made by David which are in scribed with his name. But there are also some who think none of them were made by him except those which are marked “Of David;” but those which have in the title “For David” have been made by others who assumed his person. Which opinion is refuted by the voice of the Saviour Himself in the Gospel, when He says that David himself by the Spirit said Christ was his Lord; for the 110th Psalm begins thus, “The Lord said unto my Lord, Sit Thou at my right hand, until I make Thine enemies Thy footstool.” And truly that very psalm, like many more, has in the title, not “of David,” but “for David.” But those seem to me to hold the more credible opinion, who ascribe to him the authorship of all these hundred and fifty psalms, and think that he prefixed to some of them the names even of other men, who prefigured something pertinent to the matter, but chose to have no man’s name in the titles of the rest, just as God inspired him in the management of this variety, which, although dark, is not meaningless. Neither ought it to move one not to believe this that the names of some prophets who lived long after the times of king David are read in the inscriptions of certain psalms in that book, and that the things said there seem to be spoken as it were by them. Nor was the prophetic Spirit unable to reveal to king David, when he prophesied, even these names of future prophets, so that he might prophetically sing something which should suit their persons; just as it was revealed to a certain prophet that king Josiah should arise and reign after more than three hundred years, who predicted his future deeds also along with his name.