"The Transfiguration was not a new miracle, but the temporary pause of an ongoing miracle. The real miracle was that Jesus, most of the time, could keep from displaying His glory.
“For Christ to be glorious was almost a less matter than for him to restrain or hide his glory. It is forever his glory that he concealed his glory; and that, though he was rich, for our sakes he became poor.”
(Dave Guzik)