Albert Barnes Commentary Ezekiel 38:17

"Thus saith the Lord Jehovah: Art thou he of whom I spake in old time by my servants the prophets of Israel, that prophesied in those days for [many] years that I would bring thee against them?" — Ezekiel 38:17 (ASV)

Gog - is not mentioned by name in any existing prophecy before Ezekiel’s time. The reference here shows:

1. that the conflict with Gog does not represent a particular event, but one of which the prophets in general had to speak;
2. that in the interpretation of Old Testament prophecy we are to look beyond special fulfillments.

Events in the world’s history come within a prophet’s view as parts of the divine administration by which evil struggles against but is overcome by good. As every such conflict is a prelude to the final struggle, so its prediction has reference ultimately to the consummation here foretold.