Luke’s account of the transfiguration scene reads:

“As [Jesus] was praying the appearance of his face became different and his apparel became glitteringly white. Also, look! two men were conversing with him, who were Moses and Elijah. These appeared with glory and began talking about his departure [Greek, exodos] that he was destined to fulfill at Jerusalem. Now Peter and those with him were weighed down with sleep; but when they got fully awake they saw his glory and the two men standing with him. And as these were being separated from him, Peter said to Jesus: ‘Instructor, it is fine for us to be here, so let us erect three tents, one for you and one for Moses and one for Elijah,’ he not realizing what he was saying. But as he was saying these things a cloud formed and began to overshadow them. As they entered into the cloud, they became fearful. And a voice came out of the cloud, saying: ‘This is my Son, the one that has been chosen. Listen to him.’ And as the voice occurred Jesus was found alone.”​—Luke 9:29-36.

The vision must have occurred at night, for they were sleepy, and they did not come down from the mountain until the next day. But they were awake when they saw the transfiguration. Imagine the apostles’ amazement as they saw Jesus’ face shining as the sun, and his clothing glitteringly white! Long previously Moses, after returning from the mountain where God spoke with him, could hide the brilliance of his face by a veil, but the far greater glory of Christ made even his entire apparel brilliant, glistening.​—Ex. 34:29-35; compare 2 Corinthians 3:7-11.

EVIDENCE OF CHRIST’S COMING GLORY

Here, before the apostles’ eyes, was evidence that Jesus’ presence in Kingdom power would be a glorious heavenly one. Also, the conversation of the visionary Moses and Elijah about Jesus’ exodus was proof that his humiliating death was not something to avoid, as Peter had desired. In this tableau, Moses, who was used by God to give the Law to Israel, represented that Law covenant. Elijah represented the other prophets. Both the Law and the prophets had foretold Christ, his life, his suffering, his sacrifice, his glory. All pointed to Christ.

Christ would conduct a work like Elijah. The prophet Malachi had recorded Jehovah’s promise: “Look! I am sending to you people Elijah the prophet before the coming of the great and fear-inspiring day of Jehovah.” Elijah had done a great work toward restoring pure worship. (1 Ki. 18:25-29, 40) John the Baptist did this toward Israel. (Luke 1:17; Matt. 17:12, 13) But, at the time of the transfiguration, this John was dead. Elijah appearing in the vision would therefore indicate that Christ would conduct a greater work, restoring pure worship permanently. This had to take place “before the coming of the great and fear-inspiring day of Jehovah,” that will take place when God executes judgment on false worshipers and this present wicked system of things.​—Mal. 4:5, 6.

The vision was so real that Peter began to participate in the scene, evidently overwhelmed with awe and appreciation. When he observed the two visionary men “being separated from [Jesus],” he apparently did not want them to leave. So he spoke about erecting tents, “not realizing what he was saying.”

However, the occurrence was a vision, Moses and Elijah being only visionary. (Matt. 17:9)