Suddenly they saw two men, Moses and Elijah, talking to him. They appeared in glory and were speaking of his departure, which he was about to accomplish at Jerusalem. When the voice had spoken, Jesus was found alone. And they kept silent and in those days told no one any of the things they had seen. Religion, as I'll define it, gets its meaning from the Latin root that gives us our word ligament.
Ligaments bind the bones of the body together.
At a point of turning in his life and ministry, Jesus took some friends and went up on a mountain to pray. The purpose of the climb was prayer, and prayer is often the setting of revelation. Moses and Elijah are present, and they appear in glory, a further sign of divine presence. They spoke of Jesus' departure, in Greek exodos, an obvious tie to the central affirmation of their experience with God. There is a cloud, a consistent sign of God's presence.