7 It can be taken also in this sense: “Arise, O Lord, in Your anger, and be exalted in the borders of mine enemies:” that is, arise in Your anger, and let not mine enemies understand You; so that to “be exalted,” should be this, become high, that You may not be understood; which has reference to the silence spoken of above. For it is of this exaltation thus said in another Psalm, “And He ascended upon Cherubim, and flew:” and, “He made darkness His secret place.” In which exaltation, or concealment, when for their sins' desert they shall not understand You, who shall crucify You, “the congregation” of believers “shall surround You.”
For in His very humiliation He was exalted, that is, was not understood. So that, “And arise, O Lord my God, in the commandment that You have given:” may have reference to this, that is, when Thou showest Yourself, be high or deep that mine enemies may not understand You. Now sinners are the enemies of the just man, and the ungodly of the godly man. “And the congregation of the people shall surround You:” that is, by this very circumstance, that those who crucify You understand You not, the Gentiles shall believe in You, and so “shall the congregation of the people surround You.”
But what follows, if this be the true meaning, has in it more pain, that it begins already to be perceived, than joy that it is understood. For it follows, “and for their sakes return Thou on high,” that is, and for the sake of this congregation of the human race, wherewith the Churches are crowded, return Thou on high, that is, again cease to be understood. What then is, “and for their sakes,” but that this congregation too will offend You, so that You may most truly foretell and say, “Thinkest Thou when the Son of man shall come, He will find faith on the earth?” Again, of the false prophets, who are understood to be heretics, He says, “Because of their iniquity the love of many shall wax cold.” Since then even in the Churches, that is, in that congregation of peoples and nations, where the Christian name has most widely spread, there shall be so great abundance of sinners, which is already, in great measure, perceived; is not that famine of the word here predicted, which has been threatened by another prophet also?
Is it not too for this congregation's sake, who, by their sins, are estranging from themselves that light of truth, that God returns on high, that is, so that faith, pure and cleansed from the corruption of all perverse opinions, is held and received, either not at all, or by the very few of whom it was said, “Blessed is he that shall endure to the end, the same shall be saved”? Not without cause then is it said, “and for the sake of this” congregation “return Thou on high:” that is, again withdraw into the depth of Your secrecy, even for the sake of this congregation of the peoples, that has Your name, and does not Your deeds.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)