Mark 9 - G. Campbell Morgan's Exposition on the Whole Bible

Here we see four men who have passed without death into the atmosphere and society of the heavens. One only of the four is there by His own right. Pure and spotless humanity stands in the glory of the unsullied light, and holds familiar converse with the spirits of just men.

We pass from the mountain to the valley. There we see Jesus, the baffled disciples, the father, the departing demon tearing his victim. The majesty and power of the Lord are manifested. Again He led these men through Galilee in privacy, and taught them, and the subject was still the Cross.