The writer uses this negative statement to emphasize the positive. AT: "speaks so that everyone can hear him" (See: [[rc://en/ta/man/translate/figs-litotes]])
The writer speaks of a fire burning things as if it were eating them. AT: "a fire burns in front of him" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Possible meanings are 1) God is calling on all who live in heaven and on earth to be witnesses as he judges his people or 2) God is speaking to heaven and earth as if they are people, and he is calling them to be witnesses as he judges his people. (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-personification]])