Transfiguration, Monastery of St. Catherine, Sinai

The Transfiguration of Christ is preparation for the Cross. And the Cross of Christ is the commencement of His Glory as man. By His Transfiguration, Christ does not acquire anything new; rather, He strengthens His Disciples in view of His Crucifixion. His Disciples are in need of this strengthening, in order to face the Cross of their Teacher, as well as their own cross, later, for the Name of their Teacher.
— George Mantzarides, Transfiguration and the Cross; & St Gregory Palamas (1296-1357), Archbishop of Thessalonica, Sermon on the Transfiguration.
On the Mountain You were Transfigured, O Christ God,
And Your disciples beheld Your glory as far as they could see it;
So that when they would behold You crucified,
They would understand that Your suffering was voluntary,
And would proclaim to the world,
That You are truly the Radiance of the Father!
— Kontakion, Feast of the Transfiguration
You err, Peter, … Do not seek for three tabernacles, since one is the dwelling place of the Gospel: in which are summed up both the Law and the Prophets. But if you do seek for three tabernacles, do not place the servants on the same level with their Master. But make three tabernacles; rather, make but one, for the Father, Son, and Holy Ghost; so that as one is their Divinity, so let one be their tabernacle, and let that one be in thy own breast.
— St. Jerome
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
They shall see the Lord face to face and bear his name on their foreheads. The night shall be no more. They will need no light from lamps or the sun, for the Lord God shall give them light, and they shall reign forever.
— Revelation 22:3-4
"This is my Son, the Beloved.  Listen to him."
Then suddenly, when they looked around, they saw no one with them any more but only Jesus.

Mark 9:8

 

Atacama Desert, Chile 1960.  Photograph by Jim Price (1930-2004)