1 As the Scripture is wont to set mysteries of the Psalms on the titles, and to deck the brow of a Psalm with the high announcement of a Mystery, in order that we that are about to go in may know (when as it were upon the door-post we have read what within is doing) either of whom the house is, or who is the owner of that estate: so also in this Psalm there has been written a title, of a title. For it has, “At the end, corrupt not for David himself unto the inscription of the title.”
This is that which I have spoken of, title of Title. For what the inscription of this title is, which to be corrupted he forbids, the Gospel to us does indicate. For when the Lord was being crucified, a title by Pilate was inscribed and set, “King of the Jews,” in three tongues, Hebrew, Greek, and Latin: which tongues in the whole world mostly do prevail....Therefore “corrupt not” is most proper and prophetic; since indeed even those Jews made suggestion at that time to Pilate, and said, “Do not write King of the Jews, but write, that Himself said that He was King of the Jews:” for this title, say they, has established Him King over us. And Pilate, “What I have written, I have written.” And there was fulfilled, “corrupt not.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)