For an explanation of the present Feast and understanding of its truth, it is necessary for us to turn to the very start of today’s reading from the Gospel: “Now after six days Jesus took Peter, James and John his brother, and led them up onto a high mountain by themselves” (Mt 17:1).
First of all we must ask, from whence does the Evangelist Matthew begin to reckon with six days? From what sort of day be it? What does the preceding turn of speech indicate, where the Savior, in teaching His disciples, said to them: “For the Son of Man shall come with his angels in the glory of His Father,” and further: “Again I say to you, there are some standing here who shall not taste death, until they have seen the Son of Man coming in His Kingdom” (Mt 16:27-28)? That is to say, it is the Light of His own forthcoming Transfiguration which He terms the Glory of His Father and of His Kingdom.
The Evangelist Luke points this out and reveals this more clearly saying: “Now it came to pass about eight days after these words, that He took Peter and John and James, and went up the mountain to pray. And as He prayed, His countenance was altered, and His raiment became a radiant white” (Lk 9:28-29). But how can the two be reconciled, when one of them speaks definitively about the interval of time as being eight days between the sayings and the manifestation, whereas the other (says): “after six days?”
There were eight on the mountain, but only six were visible. Three, Peter, James and John, had come up with Jesus, and they saw Moses and Elias standing there and conversing with Him, so altogether there were six of them. However, the Father and the Holy Spirit were invisibly with the Lord: the Father, with His Voice testifying that this was His Beloved Son, and the Holy Spirit shining forth with Him in the radiant cloud. Thus, the six are actually eight, and there is no contradiction regarding the eight. Similarly, there is no contradiction with the Evangelists when one says “after six days,” and the other says “eight days after these words.”
But these twofold sayings as it were present us a certain format set in mystery, and together with it that of those actually present upon the Mount. It stands to reason, and everyone rationally studying in accordance with Scripture knows that the Evangelists are in agreement one with another. Luke spoke of eight days without contradicting Matthew, who declared “after six days.” There is not another day added on to represent the day on which these sayings were uttered, nor is the day on which the Lord was transfigured added on (which a rational person might reasonably imagine to be added to the days of Matthew).
The Evangelist Luke does not say “after eight days” (like the Evangelist Matthew says “after six days”), but rather “it came to pass eight days after these words.” But where the Evangelists seem to contradict one another, they actually point out to us something great and mysterious. In actual fact, why did the one say “after six days,” but the other, in ignoring the seventh day, have in mind the eighth day? It is because the great vision of the Light of the Transfiguration of the Lord is the mystery of the Eighth Day, i.e., of the future age, coming to be revealed after the passing away of the world created in six days.
About the power of the Divine Spirit, through Whom the Kingdom of God is to be revealed, the Lord predicted: “There are some standing here who shall not taste death, until they have seen the Son of Man coming in His Kingdom” (Mt 16:28). Everywhere and in every way the King will be present, and everywhere will be His Kingdom, since the advent of His Kingdom does not signify the passing over from one place to another, but rather the revelation of its power of the Divine Spirit. That is why it is said: “come in power.” And this power is not manifest to simple ordinary people, but to those standing with the Lord, that is to say, those who have affirmed their faith in Him like Peter, James and John, and especially those who are free of our natural abasement. Therefore, and precisely because of this, God manifests Himself upon the Mount, on the one hand coming down from His heights, and on the other, raising us up from the depths of abasement, since the Transcendent One takes on mortal nature. Certainly, such a manifest appearance by far transcends the utmost limits of the mind’s grasp, as effectualized by the power of the Divine Spirit.
Thus, the Light of the Transfiguration of the Lord is not something that comes to be and then vanishes, nor is it subject to the sensory faculties, although it was contemplated by corporeal eyes for a short while upon an inconsequential mountaintop. But the initiates of the Mystery, (the disciples) of the Lord at this time passed beyond mere flesh into spirit through a transformation of their senses, effectualized within them by the Spirit, and in such a way that they beheld what, and to what extent, the Divine Spirit had wrought blessedness in them to behold the Ineffable Light.
Those not grasping this point have conjectured that the chosen from among the Apostles beheld the Light of the Transfiguration of the Lord by a sensual and creaturely faculty, and through this they attempt to reduce to a creaturely level (i.e., as something “created”) not only this Light, the Kingdom and the Glory of God, but also the Power of the Divine Spirit, through Whom it is meet for Divine Mysteries to be revealed. In all likelihood, such persons have not heeded the words of the Apostle Paul: “Eye has not seen, nor ear heard, nor has it entered into the heart of man, what things God has prepared for those who love Him. But to us God has revealed them through His Spirit. For the Spirit searches all things, even the deep things of God” (1 Cor 2:9-10).
So, with the onset of the Eighth Day, the Lord, taking Peter, James and John, went up on the Mount to pray. He always prayed alone, withdrawing from everyone, even from the Apostles themselves, as for example when with five loaves and two fish He fed the five thousand men, besides women and children (Mt 14:19-23). Or, taking with Him those who excelled others, as at the approach of His Saving Passion, when He said to the other disciples: “Sit here while I go over there and pray” (Mt 26:36). Then He took with Him Peter, James and John. But in our instance right here and now, having taken only these same three, the Lord led them up onto a high mountain by themselves and was transfigured before them, that is to say, before their very eyes.
~St Gregory Palamas, Archbishop of Thessalonica (1296 – 1359), taken from Pravoslavie.Ru: http://www.pravoslavie.ru/english/38767.htm.