Here then is our Student: himself a study for all who are anxious to comprehend this book. There are only three orders of being by whom God has spoken to the world: Christ; the angels; and _men_. And among these men the prophets hold the first rank. At an early period--the elements of religion being already revealed--a new method of communicating truth was employed; and man rose from the position of an _observer_, to the dignity and majesty of the prophet. In some instances he is removed at once into this office without previous training. But generally God walks among "the schools of the prophets;" and laying his hand upon the chosen one, He bids him go forth. His very call seems to constitute him an extraordinary man. Both his appearance and actions make him singular. He stands alone. The mountain or the sequestered vale is his abode; and he is only seen among men when he has some message from God. Clothed in his sackcloth, he appears at the court, the city, and the village; and having pronounced the coming woe, or stated the imposed duty, or offered pardon, he mysteriously disappears; and is seen no more, till the burden is again upon him, and forces him to come forth and speak. There is a fire in his eye, but it is inspiration, not wildness. There is a majesty in his gait, as though he is either great himself, or is employed by one who is. There is a solemnity of countenance and a nobility of manner, which say that he is not often among mortals, but dwells in a higher sphere. In language which more fully pertains to us as Christians, his "conversation is in heaven." Carried up by the Spirit perhaps to the summit of the mountain which covers his retreat, views of the future break upon his vision. His eye burns; his lips quiver; his bosom heaves. And opening his mouth, he pours forth in more than angelic cadences, the designs of God concerning men, and kingdoms, and the human race. It may be that to himself all this is a mystery. He therefore gathers up every utterance, and carries them to his mountain home. In that consecrated cave he spreads out the panorama; and lifting up his eyes to heaven for light, he traces the picture to see what "the Spirit of Christ which was in" him "did signify." "Sweet is the harp of prophecy; too sweet Not to be wronged by a mere mortal touch, Nor can the wonders it records be sung To meaner music, and not suffer loss." II. THE THEME.--It is here presented in a twofold aspect. First, in its _entirety_: and secondly, in one of its _branches_. 1. The great subject of prophetic enquiry is _salvation_. "Of which _salvation_ the prophets have enquired and searched diligently."