Mark 9:5

CHRYSOSTOM.f Again, Peter neither comprehended that the Lord worked His transfiguration for the showing forth of His true glory, nor that He did this in order to teach men, nor that it was impossible for them to leave the multitude and dwell in the mountain. It goes on, For they were sore afraid. But this fear of theirs was one by which they were raised from their usual state of mind to one higher, and they recognised that those who appeared to them were Moses and Elias. The soul also was drawn on to a state of heavenly feeling, as though carried away from human sense by the heavenly vision.

(ubi sup.) If the transfigured humanity of Christ and the society of but two saints seen for a moment, could confer delight to such a degree that Peter would, even by serving them, stay their departure, how great a happiness will it be to enjoy the vision of Deity amidst choirs of Angels for ever? It goes on, For he wist not what to say; although, however, Peter from the stupor of human frailty knew not what to say, still he gives a proof of the feelings which were within him; for the cause of his not knowing what to say, was his forgetting that the kingdom was promised to the Saints by the Lord not in any earthly region, but in heaven; he did not remember that he and his fellow-Apostles were still hemmed in by mortal flesh and could not bear the state of immortal life, to which his soul had already carried him away, because in our Father's house in heaven, a house made with hands is not needed. But again even up to this time he is pointed at, as an ignorant man, who wishes to make three tabernacles for the Law, the Prophets, and the Gospel, since they in no way can be separated from each other.

Or else, Peter, fearing to come down from the mount because he had now a presentiment that Christ must be crucified, said, It is good for us to be here, and not to go down there, that is, in the midst of the Jews; but if they who are furious against Thee come hither, we have Moses who beat down the Egyptians, we have also Elias, who brought fire down from heaven and destroyed the five hundred.