The Feast of the Transfiguration is celebrated each year on August 6 (o.s.). The feast commemorates the transfiguration or metamorphosis of Christ on Mount Tabor, when our Lord appeared in His divine glory before the Apostles Peter, James, and John shortly before his saving Passion.
Thou wast transfigured on the mountain, O Christ our God, showing to Thy disciples Thy glory as each one could endure; shine forth Thou on us, who are sinners all, Thy light ever-unending. Through the prayers of the Theotokos. O Light-giver, glory to Thee.
On the mount Thou wast transfigured, and Thy disciples, as much as they could bear, beheld Thy glory, O Christ God; so that when they should see Thee crucified, they would know Thy passion to be willing, and would preach to the world that Thou, in truth, art the Effulgence of the Father.
An Excerpt from St. Gregory Palamas’s Homily on The Transfiguration.
But let us not tire our attention with the furthermost interpretations of the words of the Gospel. We shall believe thus, as those same ones have taught us, who themselves were enlightened by the Lord Himself, insofar as they alone know this well: the Mysteries of God, in the words of a prophet, are known to God alone and His perpetual
...purifying our spiritual eyes of worldly thoughts...