John Gill Commentary Revelation 1:15

"and his feet like unto burnished brass, as if it had been refined in a furnace; and his voice as the voice of many waters." — Revelation 1:15 (ASV)

And his feet like unto fine brass, as if they burned in a furnace By which is meant, not his human nature in a suffering state; or his people, the meaner and lower parts of his mystical body, in a like state; or his apostles and ministers, who are supporters of his church, and run to and fro with spiritual knowledge, for which, though they suffer much, are permanent and glorious; but either the power of Christ in bearing up and supporting his people, in the care and government and defence of them; or his ways, works, and walks in his churches, and all his providential administrations towards them, which are holy, just, and righteous, and will be manifest; or his wrath and vengeance in treading down and trampling upon his enemies:

and his voice as the sound of many waters; meaning his Gospel, as preached by his apostles and ministers, which was heard far and near; see (Romans 10:18); and which made a great noise in the world; or his voice of vengeance on his enemies, which will be very terrible and irresistible.