Transfiguration icon, Theophanes the Greek, 15th cent.
Now it came to pass, about eight days after these sayings, that He took Peter, John, and James and went up on the mountain to pray. As He prayed, the appearance of His face was altered, and His robe became white and glistening. And behold, two men talked with Him, who were Moses and Elijah, who appeared in glory and spoke of His decease which He was about to accomplish in Jerusalem. But Peter and those with him were heavy with sleep; and when they were fully awake, they saw His glory and the two men who stood with Him. Then it happened, as they were parting from Him, that Peter said to Jesus, "Master, it is good for us to be here; and let us make three tabernacles: one for You, one for Moses, and one for Elijah" -- not knowing what he said. While he was saying this, a cloud came and overshadowed them; and they were fearful as they entered the cloud. And a voice came out of the cloud, saying, "This is My beloved Son. Hear Him!" When the voice had ceased, Jesus was found alone. But they kept quiet, and told no one in those days any of the things they had seen.
- Luke 9:28-36In yesterday's reading, Jesus was first alone praying; when joined by His disciples, He asked them, "Who do the crowds say that I am?" They said, "John the Baptist, but some say Elijah and others say that one of the old prophets has risen up again." He said to them, "But who do you say that I am?" Peter answered and said, "The Christ of God." Jesus warned them to tell no one, and said, "The Son of Man must suffer many things, and be rejected by the elders and chief priests and scribes, and be killed, and be raised the third day." He taught them, ""If anyone desires to come after Me, let him deny himself, and take up his cross daily, and follow Me. For whoever desires to save his life will lose it, but whoever loses his life for My sake will save it. For what profit is it to a man if he gains the whole world, and is himself destroyed or lost? For whoever is ashamed of Me and My words, of him the Son of Man will be ashamed when He comes in His own glory, and in His Father's, and of the holy angels. But I tell you truly, there are some standing here who shall not taste death till they see the kingdom of God."
Now it came to pass, about eight days after these sayings, that He took Peter, John, and James and went up on the mountain to pray. Repeatedly in the Gospels, we're taken to a mountain. This is a place of prayer, of interaction with the divine and holy.
As He prayed, the appearance of His face was altered, and His robe became white and glistening. My study bible has a long note here: "The Transfiguration demonstrates Jesus is the Lord of glory, despite the fact that He will later suffer and die on the Cross. Jesus' humanity was filled with splendor, was made Godlike, deified. His Transfiguration is the most evident expression of our hope for glorification in God's eternal Kingdom. St. Paul writes, 'Behold, I tell you a mystery. We shall not all sleep, but we shall all be changed" (1 Cor. 15:51). And St. John writes, 'We know that when He is revealed, we shall be like Him, for we shall see Him as He is' (1 John 3:2). For eternity, we shall be like Jesus as He appeared on the Mount of Transfiguration." The light in this image is a light that shines in the darkness, an "uncreated light" in the words of the Eastern Church, often appearing with a blue tinge in icons to denote its "whiter than white" appearance; it's a soft and "cool" light, one that doesn't burn but illuminates.
And behold, two men talked with Him, who were Moses and Elijah, who appeared in glory and spoke of His decease which He was about to accomplish in Jerusalem. Here, the language is important: in the Greek, "decease" is translated from the word exodos. Moses and Elijah, says my study bible, appear in the glory which reveals the transfiguration of our humanity. They are representatives of the Law and the Prophets, giving us the image of the fulfillment of the Old Testament. Of the use of the word exodos, my study bible says, "This term makes it clear that through His death Jesus will perform an exodus from Jerusalem, in which He will deliver mankind from the slavery of the evil one. It is revealed to the disciples at His Transfiguration that He will suffer, so when they see Him crucified, they will remember this day of glory and that His suffering is completely volitional." This image makes it clear that Jesus' Passion is met in the confidence of faith, of communion with God. He speaks of His exodos with Moses and Elijah, a conference on a holy mountaintop in the context of the salvation plan of God.
But Peter and those with him were heavy with sleep; and when they were fully awake, they saw His glory and the two men who stood with Him. Then it happened, as they were parting from Him, that Peter said to Jesus, "Master, it is good for us to be here; and let us make three tabernacles: one for You, one for Moses, and one for Elijah" -- not knowing what he said. The tabernacles or booths (or tents) that Peter suggests are not that far off from an understanding of exodos. The Feast of the Coming Kingdom (or Succoth) was one which celebrated the time Israel lived in tents, during the Exodus from Egypt toward the Promised Land.
While he was saying this, a cloud came and overshadowed them; and they were fearful as they entered the cloud. And a voice came out of the cloud, saying, "This is My beloved Son. Hear Him!" When the voice had ceased, Jesus was found alone. But they kept quiet, and told no one in those days any of the things they had seen. The cloud on the mountaintop is another reminder of Moses, as well as the voice from the Father. We are in a lineage of events of Israel's (and the world's) salvation. My study bible says that "Peter, James and John kept quiet because the Lord commanded them not to speak of this experience in those days, meaning until after the Resurrection."
What does it mean to have a "mountaintop" experience? What is it when we meet God in a place in which prayer becomes a medium for living and experiencing who we are? A mountaintop experience can be one in which we have a quiet insight, an understanding that teaches us where we need to be, something that reveals direction. Recently I spoke with a young man who told me of being arrested quite unfairly for something unexpected (an old traffic ticket he couldn't recall). For inexplicable reasons, he wasn't allowed to pay a fine but rather, at 18 years old, incarcerated. Due to bureaucratic procedures in the facility and overcrowding, he was put in solitary confinement, and forgotten about in yet another oversight. He spent six days in this cell. He told me it was the best thing that could have happened to him at the time; he asked for a bible and read and studied, and wrote, and thought about his life. To this day he feels it was a God-given time-out, something that would set his life in a good direction, and is most grateful for the experience. I would say that he was taken aside for a kind of mountaintop experience, an encounter with grace, with Christ in his life at a time he really needed such an intervention to teach him about his future, and to make his choices strong. So a "mountaintop experience" can come to us in all kinds of ways, but it all depends on our openness to it. Life doesn't always work with a kind of understanding that sets us apart in a spectacular way, but God does come to us and set us apart in the cool softness of this light, in this place of the heart. In prayer and communion, we may find that place that helps set us on the right road, prepare us for what is to come, and give us the acceptance of the things that are ours to choose. Let prayer be the "place" that helps you, and others, to those choices.