3 Suddenly there appeared to them Moses and Elijah, talking with him. 4 Then Peter said to Jesus, "Lord, it is good for us to be here; if you wish, I will make three dwellings here, one for you, one for Moses, and one for Elijah." 5 While he was still speaking, suddenly a bright cloud overshadowed them, and from the cloud a voice said, "This is my Son, the Beloved; with him I am well pleased; listen to him!" 6 When the disciples heard this, they fell to the ground and were overcome by fear. 7 But Jesus came and touched them, saying, "Get up and do not be afraid." 8 And when they looked up, they saw no one except Jesus himself alone. 9 As they were coming down the mountain, Jesus ordered them, "Tell no one about the vision until after the Son of Man has been raised from the dead." 10 And the disciples asked him, "Why, then, do the scribes say that Elijah must come first?" 11 He replied, "Elijah is indeed coming and will restore all things; 12 but I tell you that Elijah has already come, and they did not recognize him, but they did to him whatever they pleased. So also the Son of Man is about to suffer at their hands." 13 Then the disciples understood that he was speaking to them about John the Baptist.
Matthew Henry's Commentary on Matthew 17:3-13
Commentary on Matthew 17:1-13
(Read Matthew 17:1-13)
Now the disciples beheld somewhat of Christ's glory, as of the only begotten of the Father. It was intended to support their faith, when they would have to witness his crucifixion; and would give them an idea of the glory prepared for them, when changed by his power and made like him. The apostles were overcome by the glorious sight. Peter thought that it was most desirable to continue there, and to go no more down to meet the sufferings of which he was so unwilling to hear. In this he knew not what he said. We are wrong, if we look for a heaven here upon earth. Whatever tabernacles we propose to make for ourselves in this world, we must always remember to ask Christ's leave. That sacrifice was not yet offered, without which the souls of sinful men could not have been saved; and important services were to be done by Peter and his brethren. While Peter spoke, a bright cloud overshadowed them, an emblem of the Divine presence and glory. Ever since man sinned, and heard God's voice in the garden, unusual appearances of God have been terrible to man. They fell prostrate to the earth, till Jesus encouraged them; when looking round, they beheld only their Lord as they commonly saw him. We must pass through varied experiences in our way to glory; and when we return to the world after an ordinance, it must be our care to take Christ with us, and then it may be our comfort that he is with us.