The Unity of Isaiah
The chief reasons for this are theological, for it is argued that the glowing predictions of salvation to come are not to be found in preexilic prophecy. Apart from the fact that (1) this view begs the question (cf. Micah 4), it must also be asked (2) why redactors felt encouraged to add these passages to Isaiah if the original form of the prophecy was so uniformly negative. Why not to Amos or Micah or Jeremiah? For that theory to be accepted, the original form of the book will have had to have contained the Judgment/Hope motif in more than a germinal way. Of course, if that is granted, then (3) the whole theory of redactions which subtly altered the impact of the book becomes questionable.
Of even more serious import, however, are the theological questions which this point of view raises. The supposed redactors, by putting their words and points of view into the mouth of the older prophet, are (4) making a theological statement which is patently untrue. They are saying “If we repent, there is hope for us, because it was foretold by Isaiah. But, if the causal link is in fact false, their opinions are without force. The redactors have then falsified their evidence to win a case. Can this be the source of some of the world’s great theology?
Finally, there is (5) a literary question. As the text stands now, it has an internal logic: your plans are stupid and corrupt because you will not believe the simplicity of God’s promises. If in fact the prophet had no promises of redemption, what is it the rulers were rejecting? If it be said he had promises, but not these, we are (6) faced once again with redactors whose ethics are decidedly questionable, for they have excised the original promises and replaced them with their own.
- John Oswalt, Isaiah 1-39, 535