Mark 9:5

And Peter answereth and saith to Jesus, Rabbi, it is good for us to be here: and let us make three tabernacles; one for thee, and one for Moses, and one for Elijah.

Of course, Peter was wrong in this suggestion, and yet it is easy to understand his feelings. It was a glorious thing they had just seen, and how natural it was that he should have desired to prolong such a glorious fellowship. As Erdman said:

Peter is not to be ridiculed; he realized the blessedness of the experience; however clumsily expressed; (and) in spite of his fear, he wished to continue in such blissful companionship.[7]

Peter's desire was like that of many in all generations who experience some glorious achievement or magnificent event and thereafter seek to perpetuate endlessly the glory of that moment. Such a desire, even if it were possible of fulfillment, should not prevail. Life is not designed to freeze some glorious moment like the figures on a Grecian urn. Whatever sweet and precious moments may be provided by life on earth, they can never be permanent; there is always the journey down the mountain; and so it was for the blessed three who participated in the transfiguration.

Peter's failure here was in the supposition that Jesus AND Moses AND Elijah were in some manner a greater authority or more desirable fellowship than that of Jesus alone, a notion that was quickly corrected by the event of the cloud and the voice out of heaven, after which they saw "Jesus only." In our own times, the human temptation to mix the word and teachings of Christ with some other system exhibits the same error that Peter made here. It is not Christianity with something else that blesses people; it is Christianity alone.

Tabernacles ... This word was the one used to describe the arbors or booths in which the people of Israel dwelt briefly during the annual feast of Tabernacles; but the exact nature of what Peter here had in mind is unknown.