2 Six days later Jesus took Peter, James, and John, and led them up a high mountain to be alone. As the men watched, Jesus' appearance was transformed, 3 and his clothes became dazzling white, far whiter than any earthly bleach could ever make them. 4 Then Elijah and Moses appeared and began talking with Jesus. 5 Peter exclaimed, "Rabbi, it's wonderful for us to be here! Let's make three shelters as memorials -one for you, one for Moses, and one for Elijah." 6 He said this because he didn't really know what else to say, for they were all terrified. 7 Then a cloud overshadowed them, and a voice from the cloud said, "This is my dearly loved Son. Listen to him." 8 Suddenly, when they looked around, Moses and Elijah were gone, and they saw only Jesus with them.
Matthew Henry's Commentary on Mark 9:2-8
Commentary on Mark 9:1-13
(Read Mark 9:1-13)
Here is a prediction of the near approach Christ's kingdom. A glimpse of that kingdom was given in the transfiguration of Christ. It is good to be away from the world, and alone with Christ: and how good to be with Christ glorified in heaven with all the saints! But when it is well with us, we are apt not to care for others, and in the fulness of our enjoyments, we forget the many wants of our brethren. God owns Jesus, and accepts him as his beloved Son, and is ready to accept us in him. Therefore we must own and accept him as our beloved Saviour, and must give up ourselves to be ruled by him. Christ does not leave the soul, when joys and comforts leave it. Jesus explained to the disciples the prophecy about Elias. This was very suitable to the ill usage of John Baptist.