1 The Psalm which has just been sung is short, if we look to the number of its words, but of deep interest in its thoughts....The subject of song and praise in that Psalm is a city, whose citizens are we, as far as we are Christians: whence we are absent, as long as we are mortal: whither we are tending: through whose approaches, undiscoverable among the brakes and thorns that entangle them, the Sovereign of the city made Himself a path for us to reach it. Walking thus in Christ, and pilgrims till we arrive, and sighing as we long for a certain ineffable repose that dwells within that city, a repose of which it is promised, that “the eye of man has never seen” such, “nor ear heard, nor has it entered into his heart to conceive;” let us chant the song of a longing heart: for he who truly longs, thus sings within his soul, though his tongue be silent: he who does not, however he may resound in human ears, is voiceless to God. See what ardent lovers of that city were they by whom these words were composed, by whom they have been handed down to us; with how deep a feeling were they sung by those! A feeling that the love of that city created in them: that love the Spirit of God inspired; “the love of God,” he says, “shed abroad in our hearts by the Holy Ghost, which is given unto us.” Fervent with this Spirit then, let us listen to what is said of that city.
2. “Her foundations are upon the holy hills”. The Psalm had as yet said nothing of the city: it begins thus, and says, “Her foundations are upon the holy hills.” Whose? There can be no doubt that foundations, especially among the hills, belong to some city. Thus filled with the Holy Spirit, and with many thoughts of love and longing for that city, as if after long internal meditation, that citizen bursts out, “Her foundations are upon the holy hills;” as if he had already said something concerning it. And how could he have said nothing on a subject, respecting which in his heart he had never been silent? For how could “her foundations” have been written, of which nothing had been said before? But, as I said, after long and silent travailing in contemplation of that city in his mind, crying to God, he bursts out into the ears of men thus: “Her foundations are upon the holy hills.” And, supposing persons who heard to enquire of what city he spoke he adds, “the Lord loves the gates of Sion.” Behold, then, a city whose foundations are upon the holy hills, a city called Sion, whose gates the Lord loves, as he adds, “above all the dwellings of Jacob.” But what does this mean, “her foundations on the holy hills”? What are the holy hills upon which this city is built? Another citizen tells us this more explicitly, the Apostle Paul: of this was the Prophet a citizen, of this the Apostle citizen: and they spoke to exhort the other citizens. But how are these, I mean the Prophets and Apostles, citizens? Perhaps in this sense; that they are themselves the hills, upon which are the foundations of this city, whose gates the Lord loves. Let then another citizen state this clearly, that I may not seem to guess. Speaking to the Gentiles, and telling them how they were returning, and being, as it were, framed together into the holy structure, “built,” he says, “upon the foundations of the Apostles and Prophets:” and because neither the Apostles nor Prophets, upon whom the foundations of that city rest, could stand by their own power, he adds, “Jesus Christ Himself being the head comer stone.” That the Gentiles, therefore, might not think they had no relation to Sion: for Sion was a certain city of this world, which bore a typical resemblance as a shadow to that Sion of which he presently speaks, that Heavenly Jerusalem, of which the Apostle says, “which is the mother of us all;” they might not be said to bear no relation to Sion, on the ground that they did not belong to the Jewish people, he addresses them thus: “Now therefore you are no more strangers and foreigners, but fellow citizens with the saints, and of the household of God, and are built upon the foundation of the Apostles and Prophets.” You see the structure of so great a city: yet whereon does all that edifice repose, where does it rest, that it may never fall? “Jesus Christ Himself,” he says, “being the head corner stone.”
3....But that you may know that Christ is at once the earliest and the highest foundation, the Apostle says, “Other foundation can no man lay than is laid, which is Christ Jesus.” How, then, are the Prophets and Apostles foundations, and yet Christ so, than whom nothing can be higher? How, think you, save that as He is openly styled, Saint of saints, so figuratively Foundation of foundations? Thus if you are thinking of mysteries, Christ is the Saint of saints: if of a subject flock, the Shepherd of shepherds: if of a structure, the Pillar of pillars. In material edifices, the same stone cannot be above and below: if at the bottom, it cannot be at the top: and vice versa: for almost all bodies are liable to limitations in space: nor can they be everywhere or for ever; but as the Godhead is in every place, from every place symbols may be taken for It; and not being any of these things in external properties, It can be everything in figure. Is Christ a door, in the same sense as the doors we see made by carpenters? Surely not; and yet He said, “I am the door.” Or a shepherd, in the same capacity as those who guard sheep? Though He said, “I am the Shepherd.” Both these names occur in the same passage: in the Gospel, He said, that the shepherd enters by the door: the words are, “I am the good Shepherd;” and in the same passage, “I am the door:” and who is the shepherd who enters by the door? “I am the good Shepherd:” and what is the door by which Thou, Good Shepherd, enterest? How then are You all things? In the sense in which everything is through Me. To explain: when Paul enters by the door, does not Christ? Wherefore? Not because Paul is Christ: but since Christ is in Paul: and Paul acts through Christ. The Apostle says, “Do ye seek a proof of Christ speaking in me?” When His saints and faithful disciples enter by the door, does not Christ enter by the door? How are we to prove this? Since Saul, not yet called Paul, was persecuting those very saints, when He called to him from Heaven, “Saul, Saul, why do you persecute Me?” Himself then is the foundation, and corner stone: rising from the bottom: if indeed from the bottom: for the base of this foundation is the highest exaltation of the building: and as the support of bodily fabrics rests upon the ground, that of spiritual structures reposes on high. Were we building up ourselves upon the earth, we should lay our foundation on the lowest level: but since our edifice is a heavenly one, to Heaven our Foundation has gone before us: so that our Saviour, the corner stone, the Apostles, and mighty Prophets, the hills that bear the fabric of the city, constitute a sort of living structure. This building now cries from your hearts; that you may be built up into its fabric, the hand of God, as of an artificer, works even through my tongue. Nor was it without a meaning that Noah's ark was made of “square beams,” which were typical of the form of the Church. For what is it to be made square? Listen to the resemblance of the squared stone: like qualities should the Christian have: for in all his trials he never falls: though pushed, and, as it were, turned over, he falls not: and thus too, whichever way a square stone is turned, it stands erect....In earthly cities, one thing is the structure of buildings: another thing are the citizens that dwell therein: that city is built of its own inmates, who are themselves the blocks that form the city, for the very stones are living: “You also,” says the Apostle, “as living stones, are built up a spiritual house,” words that are addressed to ourselves. Let us then pursue the contemplation of that city.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)