22 What ye cried out a while ago at the very mention of peace, you cried from longing: your cry was from thirst, not from fullness; for there will be perfect righteousness where will be perfect peace. Now we hunger and thirst after righteousness. “They shall be filled.” How shall they be filled? When we have arrived at peace. Therefore when he had said, “Who has set peace for your borders,” because there is fullness and no want, he added at once, “and fills you with the fat of wheat”....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)