What's the Primary Fulfillment of the Book of Revelation?

King Ahaz was terrified of these two foreign kings and so God sends the prophet Isaiah to him to reassure him. The only way that could serve as a sign for King Ahaz hundreds of years before Christ is if there was a child born in his own day. There had to be some child in Isaiah's day to fulfill this prophecy as its primary fulfillment, then it had a later fulfillment in Jesus Christ. We shouldn't think about this as if it can have only one meaning because scriptural passages can have more than one meaning and more than one application or I can.