NOTES for Isa 9:1-21
A wonderful gift: prophecy. Several centuries after these words were written, the apostle Paul will say that we should especially seek this very gift, because it opens the Lord's ways to us.
It would seem that Isaiah is simply prophesying about the birth of an earthly Messiah, the King from the line of David, but he lists names that can refer only to God Himself. And for a person of Isaiah's time a name was not a conventional label, but something that expressed the essence of the bearer of the name.
So the King from David's line in some astonishing way turns out to be God Himself, establishing His Kingdom forever. And all this is accomplished by the zeal of God, or, as the New Testament would later clarify, by the love of God.