13 “Therefore there shall return hither My people”. Now Asaph himself is returning hither. For he saw these things abound to unrighteous men, he saw them abound to proud men: he is returning to God, and is beginning to inquire and discuss. But when? “When full days shall be found in them.” What is “full days”? “But when there came the fullness of time, God sent His Son.” This is the very fullness of time, when He came to teach men that things temporal should be despised, that they should not esteem as a great matter whatever object evil men covet, that they should suffer whatever evil men fear. He became the way, He recalled us to inward thought, admonished us of what should be sought of God. And see from what thought reacting upon itself, and in a manner recalling the waves of its impulse, he does pass over unto choosing true things.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)