Giambettino Cignaroli, Transfiguration of Christ (1741)
The account of the supernatural trans-formation of Christ is recorded in the synoptic gospels (Mark 9:2-8; Matt. 17:1-8; Luke 9:28-36). There is no mention of the event in the gospel of John, but there is a reference at 2 Pet. 1:18.
In the context of the Bible, the mention of Moses (the Law) and Elijah (the Prophets), standing with Jesus at his transfiguration and the cloud visible to the disciples as a symbol for the divine presence (Exod. 33:7-11), signify the relationship of this New Testament account to the ancient Jewish Old Testament account as told in Exodus 24:16.
We now consider Christ’s transfiguration; and the four points of inquiry answered by St. Thomas Aquinas:
Article 1. Whether it was fitting that Christ should be transfigured?
Our Lord, after foretelling His Passion to His disciples, had exhorted them to follow the path of His sufferings (Matt. 16:21, 24). Now in order that anyone go straight along a road, he must have some knowledge of the end: thus, an archer will not shoot the arrow straight unless he first sees the target. Hence Thomas said (Jn. 14:5): ” “LORD, we don’t know where you are going, so how can we know the way?” Above all is this necessary when hard and rough is the road, heavy the going, but delightful the end. Now by His Passion Christ achieved glory, not only of His soul, which He had from the first moment of His conception, but also of His body; according to Luke (24:26): “Christ ought [Vulg.: ‘ought not Christ’] to have suffered these things, and so to enter into His glory (?).” To which glory He brings those who follow the footsteps of His Passion, according to Acts 14:21: “Through many tribulations we must enter into the kingdom of God.” Therefore, it was fitting that He should show His disciples the glory of His clarity (which is to be transfigured), to which He will configure those who are His; according to Phil. 3:21: “(Who) will reform the body of our lowness configured [Douay: ‘made like’] to the body of His glory.” Hence Bede says on Mk. 8:39: “By His loving foresight He allowed them to taste for a short time the contemplation of eternal joy, so that they might bear persecution bravely.”
Article 2. Whether this clarity was the clarity of glory?
The clarity which Christ assumed in His transfiguration was the clarity of glory as to its essence, but not as to its mode of being. For the clarity of the glorified body is derived from that of the soul, as Augustine says (Ep. ad Diosc. cxviii). And in like manner the clarity of Christ’s body in His transfiguration was derived from His God head, as Damascene says (Orat. de Transfig.) and from the glory of His soul. That the glory of His soul did not overflow into His body from the first moment of Christ’s conception was due to a certain Divine dispensation, that, as stated above (Q [14], A [1], ad 2), He might fulfil the mysteries of our redemption in a passible body. This did not, however, deprive Christ of His power of outpouring the glory of His soul into His body. And this He did, as to clarity, in His transfiguration, but otherwise than in a glorified body. For the clarity of the soul overflows into a glorified body, by way of a permanent quality affecting the body. Hence bodily refulgence is not miraculous in a glorified body. But in Christ’s transfiguration clarity overflowed from His Godhead and from His soul into His body, not as an immanent quality affecting His very body, but rather after the manner of a transient passion, as when the air is lit up by the sun. Consequently, the refulgence, which appeared in Christ’s body then, was miraculous: just as was the fact of His walking on the waves of the sea. Hence Dionysius says (Ep. ad Cai. iv): “Christ excelled man in doing that which is proper to man: this is shown in His supernatural conception of a virgin and in the unstable waters bearing the weight of material and earthly feet.”
Wherefore we must not say, as Hugh of St. Victor [Innocent III, De Myst. Miss. iv] said, that Christ assumed the gift of clarity in the transfiguration, of agility in walking on the sea, and of subtlety in coming forth from the Virgin’s closed womb: because the gifts are immanent qualities of a glorified body. On the contrary, whatever pertained to the gifts, that He had miraculously. The same is to be said, as to the soul, of the vision in which Paul saw God in a rapture, as we have stated in the SS, Q [175], A [3], ad 2.
Article 3. Whether the witnesses of the transfiguration were fittingly chosen?
Christ wished to be transfigured in order to show men His glory, and to arouse men to a desire of it, as stated above (A [1]). Now men are brought to the glory of eternal beatitude by Christ—not only those who lived after Him, but also those who preceded Him; therefore, when He was approaching His Passion, both “the multitude that followed” and that “which went before, cried saying: ‘Hosanna,'” as related Mat. 21:9, beseeching Him, as it were, to save them. Consequently, it was fitting that witnesses should be present from among those who preceded Him—namely, Moses and Elias—and from those who followed after Him—namely, Peter, James, and John—that “in the mouth of two or three witnesses” this word might stand.
Article 4. Whether the testimony of the Father’s voice, saying, “This is My beloved Son,” was fittingly added?
The adoption of the sons of God is through a certain conformity of image to the natural Son of God. Now this takes place in two ways: first, by the grace of the wayfarer, which is imperfect conformity; secondly, by glory, which is perfect conformity, according to 1 Jn. 3:2: “We are now the sons of God, and it hath not yet appeared what we shall be: we know that, when He shall appear, we shall be like to Him, because we shall see Him as He is.” Since, therefore, it is in baptism that we acquire grace, while the clarity of the glory to come was foreshadowed in the transfiguration, therefore both in His baptism and in His transfiguration the natural sonship of Christ was fittingly made known by the testimony of the Father: because He alone with the Son and Holy Ghost is perfectly conscious of that perfect generation.
Summa Theologica, by St. Thomas Aquinas, Question 45.