This is your own imagination speaking, the only power that calls a thing, declares it, and sets it in order before it appears. To call is to name the state you want as already yours. To declare it is to affirm it against the evidence. To set it in order is to arrange the inner scene so that it implies the wish fulfilled, and then the coming things arrange themselves to match.
No other power stands beside this one. The ancient people were appointed by it, and every event still on its way is being shown from within before it is seen without. A person foretells his future by what he assumes himself to be now, and what he assumes with feeling comes to pass. The imagination in you is the God of Scripture, doing exactly what this passage claims: announcing the end, then bringing the world into agreement with the announcement.