Accordingly, to expound Isaiah xl.-lxvi. is really to write the religious history of Israel. A prophet whose vision includes both Abraham and Christ, whose subject is the whole meaning and promise of Israel, cannot be adequately interpreted within the limits of his own text or of his own time. Excursions are necessary both to the history that is behind him, and to the history that is still in front of him. This is the reason of the appearance in this volume of chapters whose titles seem at first beyond its scope--such as From Isaiah to the Fall of Jerusalem: What Israel took into Exile: One God, One People: The Servant of the Lord in the New Testament. Moreover, much of this historical matter has an interest that is only historical. If in Isaiah's own prophecies it is his generation's likeness to ourselves, which appeals to our conscience, in chs. xl.-lxvi. of the Book called by his name it is Israel's unique meaning and office for God in the world, which we have to study. We are called to follow an experience and a discipline unshared by any other generation of men; and to interest ourselves in matters that then happened once for all, such as the victory of the One God over the idols, or His choice of a single people through whom to reveal Himself to the world. We are called to watch work, which that representative and priestly people did for humanity, rather than, as in Isaiah's own prophecies, work which has to be repeated by each new generation in its turn, and to-day also by ourselves. This is the reason why in an exposition of Isaiah xl.-lxvi., like the present volume, there should be a good deal more of historical recital, and a good deal less of practical application, than in the exposition of Isaiah i.-xxxix.
At the same time we must not suppose that there is not very much in Isaiah xl.-lxvi. with which to stir our own consciences and instruct our own lives. For, to mention no more, there is that sense of sin with which Israel entered exile, and which has made the literature of Israel's Exile the confessional of the world; there is that great unexhausted programme of the Service of God and Man, which our prophet lays down as Israel's duty and example to humanity; and there is that prophecy of the virtue and glory of vicarious suffering for sin, which is the gospel of Jesus Christ and His Cross.
I have found it necessary to devote more space to critical questions than in the previous volume. Chs. xl.-lxvi. approach more nearly to a unity than chs. i.-xxxix.: with very few exceptions they lie in chronological order. But they are not nearly so clearly divided and grouped: their connection cannot be so briefly or so lucidly explained. The form of the prophecy is dramatic, but the scenes and the speakers are not definitely marked off. In spite of the chronological advance, which we shall be able to trace, there are no clear stages--not even, as we shall see, at those points at which most expositors divide the prophecy, the end of ch. xlix. and of ch. lviii. The prophet pursues simultaneously several lines of thought; and though the close of some of these and the rise of others may be marked to a verse, his frequent passages from one to another are often almost imperceptible. He everywhere requires a more continuous translation, a closer and more elaborate exegesis, than were necessary for Isaiah i.-xxxix.
In order to effect some general arrangement and division of Isa. xl.-lxvi. it is necessary to keep in view that the immediate problem which the prophet had before him was twofold. It was political, and it was spiritual. There was, first of all, the deliverance of Israel from Babylon, according to the ancient promises of Jehovah: to this were attached such questions as Jehovah's omnipotence, faithfulness and grace; the meaning of Cyrus; the condition of the Babylonian Empire. But after their political deliverance from Babylon was assured, there remained the really larger problem of Israel's spiritual readiness for the freedom and the destiny to which God was to lead them through the opened gates of their prison-house: to this were attached such questions as the original calling and mission of Israel; the mixed and paradoxical character of the people; their need of a Servant from the Lord, since they themselves had failed to be His Servant; the coming of this Servant, his methods and results.