He will go before him in the spirit and power of Elijah, 'to turn the hearts of the fathers to the children,' and the disobedient to the wisdom of the just; to make ready a people prepared for the Lord."
And, of course, throughout the Old Testament prophesies, there was that promise that the Messiah would sit upon the throne of David, to order it, and to establish it in righteousness and in judgment, from henceforth, even forever.