7 As though it were said, How do ye know this? All of us have sung these Psalms: and Christ, Man for our sake, God before us, sings within us all. But is this much to say, “before us,” of Him who was before heaven and earth and time? He then, born for our sakes a man, in that city, also founded her when He was the Most High. Yet how are we assured of this? “The Lord shall rehearse it when He writes up the people”, as the following verse has it. “The Lord shall declare, when He writes up the people, and their princes.”
What princes? “Those who were born in her;” those princes who, born within her walls, became therein princes: for before they could become princes in her, God chose the despised things of the world to confound the strong. Was the fisherman, the publican, a prince? They were indeed princes: but because they became such in her. Princes of what kind were they? Princes come from Babylon, believing monarchs of this world, came to the city of Rome, as to the head of Babylon: they went not to the temple of the Emperor, but to the tomb of the Fisherman.
Whence indeed did they rank as princes? “God chose the weak things of the world to confound the strong, and the foolish things He has chosen, and things which are not as though they were, that things which are may be brought to nought.” This He does who “from the ground raises the helpless, and from the dunghill exalts the poor.” For what purpose? “That He may set him with the princes, even with the princes of His people.” This is a mighty deed, a deep source of pleasure and exultation. Orators came later into that city, but they could never have done so, had not fishermen preceded them. These things are glorious indeed, but where could they take place, but in that city of God, of whom very excellent things are spoken?
Source: The Enarrations, or Expositions, on the Psalms (New Advent)