Vladimir Lossky (1903-1958) was one of the leading Orthodox theologians of the twentieth century.  For today's feast of the Transfiguration we offer an excerpt from his The Meaning of Icons (Co-author Leonid Ouspensky, St Vladimir's Seminary Press, Crestwood, New York, 1983).  The icon referred to and reproduced to the right is of the 15th century Novgorod school.

The quote is found on pp 209-212.

What is it that the three disciples were able to contemplate when they saw the face of Christ "shine as the sun" and His rainment "white as the light" when a  "bright cloud overshadowed them " (Matt 17:2, 5)?  According to St Gregory of Nazianzus this light was the Divinity manifested to the disciples on the mountain.  St John Damascene, speaking of this "splendor of the Divine nature", of this "a-temporal glory", observes that the comparison made by the Evangelists with the light of the sun remains quite inadequate, for uncreated reality cannot be expressed by a created image.  The matter in question, then, is the vision of God and it is evident why, from St Irenaeus of Lyon to Philaret of Moscow, the theme of the Transfiguration  of Christ has never ceased to feed the thought of the Fathers and theologians of the Church...St Gregory Palamas (died 1359), in defending the traditional teaching on the Lord's Transfiguration against the attacks of certain rationalist theologians, well understood how to give full value to the importance of this evangelical event for Christian dogma and spirituality.  "God is called Light", he said, "not according to His Essence, but according to His energy".  The light which illuminated the Apostles was not something sensible, but on the other hand it is equally false to see in it an intelligible reality, which would be called "light" only metaphorically.  The Divine Light is neither material nor spiritual, for it transcends the order of the created, it is "the ineffable splendor of the one nature in three hypostases"...

Christ appeared to the disciples, not in kenotic form, as  "servant", but in the "form of God", as an Hypostasis of the Trinity Who, in His Incarnation, remains inseparable from His Divine nature, which is common to the Father and the Holy Spirit...

Christ transfigured is represented standing on the summit of the mountain, speaking with Moses ans Elias.  His rainment is shining white.  The geometrical figure inscribed in the circle of the mandorla must represent the "bright cloud" which revealed the transcendant source of the Divine energies.  The three rays pointed down upon the apostles are an indication that the action of the Transfiguration is trinitarian...Moses (on the right) in our icon is holding a book; generally it is the tables of the Decalogue--Elias (on the left) is an old man with long hair...Moses represents the dead, whilst Elias, taken up to heaven on a chariot of fire, represents the living...This [interpretation] is comprehensible; it underlies  the eschatological  character of the Transfiguration.  Christ appears as the Lord of the quick and the dead, coming in the glory of the future age.  The Transfiguration was "an anticipation of His glorious Second Coming", says St Basil:  the moment which opened a perspective of eternity in time.