NOTES for Rev 10:8
Every prophet receives his revelation and passes through his calling. John is no exception. His prophetic calling takes place against the background of the end of times that is revealed to him in a vision. What is this: symbol or reality? The question, which looks quite natural, in fact turns out not to be entirely correct. A symbol is also real, and behind it stands reality. It is simply that this reality cannot be perceived by a person as it actually is. Still, the expression "as it actually is" is itself, in a certain sense, conditional.
"As it actually is" - how is that? As it is in itself? Or as God sees it? Any other view is by definition relative, and therefore it is not entirely the same as "as it actually is." God, of course, sees how it is "as it actually is," but His vision is fully and truly known only to Him alone: even when He reveals what is known to Him to someone else, this revelation, being received by an angel or by a person, still becomes something different compared with what and how God knows.
This is where symbols are born. They are needed in order to relate the meanings known to God to human perception. But the reality behind the symbol is the most genuine reality there is; it is not the fruit of human imagination, but only takes a form accessible to human perception. And if within this reality a person experiences a prophetic calling, then it is just as real as everything else that is revealed to him.
So it is with John: the picture unfolding before his gaze is symbolic, while his calling is entirely real. More than that, it closely resembles the calling, for example, of Ezekiel, one of the great prophets of the Babylonian exile. Ezekiel too had to swallow the scroll offered to him, and this too happened in a vision, only the end of times was still far away then. Thus John becomes a prophet who, judging by the angel's words, will still have to prophesy "about peoples and nations."