Thomas Aquinas, on Ps 18:1

“Unto the end. A psalm for David.”

“Above, the Psalmist gave thanks in many ways for benefits both given and hoped for; but here, from the consideration of those benefits, he rises to the praise of the Benefactor. The title is clear: "To the end, a Psalm of David." According to the letter it refers to David; but according to the mystery, to Christ, "to the end." This Psalm is divided into two parts. In the first, God is commended for his instruction by which he teaches us. And this in two ways. One is general, which applies equally to all, and this is manifested through his works: Rom. 1: "The invisible things of God are clearly seen, being understood through the things that are made." The other is special, through the giving of the law, which pertains only to the faithful. The second part begins at "The law of the Lord is unspotted." This Psalm is truly expounded of Christ, because the Apostle brings forward the authority of this passage for the mystery of Christ in Rom. 10: "Their sound has gone forth into all the earth," and so on. Nevertheless, just as the mysteries of Christ are sometimes represented figuratively in the figures of the Old Testament, so too they are sometimes figuratively foreshadowed in the figures of the works of the saints. And therefore this Psalm will first be expounded according to the figure, and secondly according to the truth. First he speaks of the heavens, then of the sun. By the heavens the apostles are understood; by the sun, Christ is understood: "In the sun." Concerning this he does two things. First he sets forth the teaching by which God instructs us through the heavens, however understood. Second, he excludes impediments to this teaching, at "Day to day utters speech," and so on. Two things are necessary to know about God. One is the glory of God, in which he is glorious. The second is his works. If we consider the corporeal heavens, they announce to us the glory of God, because in them there is a wondrous and ordered distinction, which is a certain overflow of that firmness of glory: Eccl. 43: "The beauty of heaven, the glory of the stars, the world on high shining forth, the Lord." And because "the sun giving light has looked upon all things, and the work of the Lord is full of his glory." And therefore these material heavens are understood to indicate to us the glory of God, not as living material things, as Rabbi Moses says, but in their beauty by which their Maker is much more clearly indicated. And the firmament shows us how magnificent God is. The firmament is called heaven, as it says in Gen. 1: "God called the firmament heaven." But according to the distinction, it is called heaven; and thus in the distinction of the heavens, divine wisdom appears. If the whole is taken together, it narrates his power. And therefore he says that the heavens declare, that is, manifest, the glory of God, and the firmament announces the works of his hands, through which works his power appears. But according to the truth, by the heavens the apostles are understood, in whom, as in heavens, God dwells. And they are called heavens because of the sublimity of their way of life: Phil. 3: "Our citizenship is in heaven." Likewise they are adorned with stars, because of the abundance of their many virtues: Eccl. 43: "The beauty of heaven, the glory of the stars": Is. 55: "As the heavens are exalted above the earth," and so on; because they are luminous through teaching and example: Mt. 5: "So let your light shine before men, that they may see your good works and glorify your Father who is in heaven." Because they revolve through obedience and the course of preaching: Sir. 24: "I alone have compassed the circuit of heaven, and I walked in the waves of the sea, and I penetrated the depths of the abyss, and I stood in every land, and in every people and in every nation I held the primacy." These declare the glory of God, namely of the Father, in which is Christ. And because Christ is equal to the Father, and that he is God, and that he freely forgives sins: Is. 52: "You were sold for nothing, and you shall be redeemed without money." Likewise the apostles are called the firmament, because they were strengthened by the power of the Holy Spirit: Lk. 24: "Stay in the city until you are clothed with power from on high." And they announce the works of his hands, that is, the wonderful things that Christ did, namely his nativity, passion, resurrection, and ascension: Eccl. 42: "Has not God made the saints declare all his wonders?" Is. 12: "Announce this in all the earth." Ps. 95: "Announce his glory among the nations, his wonders among all peoples." Or, the heavens declare, because the heavens sent a new star, announcing the birth of the Savior: Mt. 2: "We saw his star in the east."”

Imported from an open dataset — not yet checked against the printed edition.