Of the increase of his government and peace there shall be no end. The Messiah's kingdom shall ever increase more and more; there shall be no limits to it; ultimately it shall fill the world (comp. Matthew 28:18, Matthew 28:19).
The continual spread of Christianity tends to the accomplishment of this prophecy. Upon the throne of David, and upon his kingdom. That the Messiah is to sit on the throne of David, suggests, but does not absolutely imply, his Davidic descent.
That descent is, however, announced with sufficient clearness in Isaiah 11:1, Isaiah 11:10. To order it, and to establish it. A gradual establishment of the kingdom would seem to be implied, such as is taught also in the parables of the mustard seed and the leaven.
From henceforth even forever. The kingdom is to be both universal in respect of extent (see the first note on the verse), and in respect of duration eternal. The zeal; or, jealousy. God's jealousy of his own honor, which is bound up with the prosperity and final triumph of his people over all their enemies, will assure the performance of all that is here prophesied.