Mark 9:5

Peter had forgotten that the glorious kingdom of Christ was not of this world, but in heaven only; that himself and the other apostles, clothed as they were with their mortality, could not participate in immortal joys; and that the mansions in the house of the Father are not raised with human hands. He again shewed that he knew not what he said, by wishing to make three tabernacles, one for the law, one for the prophets, and one for the gospel, since these three cannot be separated from each other. (Ven. Bede)