I finished Otto Kaiser's commentary from the 1960's on Isaiah 1-12. My goal in this post is to address a question: Why does Kaiser attribute certain passages in the Book of Isaiah to Isaiah, but other passages to a later redactor or interpolator? Tomorrow, I'll get into cool points Kaiser makes that actually highlight the meaning of the text.
In Isaiah 1:2-9, there is a chastisement of Judah for her rebellion against the LORD, a remark about the desolation of the country and its cities, and an expression of wonder that God left survivors, thereby preventing Judah from becoming like Sodom and Gomorrah. Kaiser thinks that this passage was placed in its prominent position within the book at a late stage in the Book of Isaiah's formation. The passage appears to be a summary in that "it seems to contain in a concise form the whole legacy of the prophet to posterity: it is only thanks to the grace of God that Israel has not wholly succumbed to the judgment which has threatened it time and time again since the days of Isaiah" (page 6). My initial impression is that Kaiser is arguing that Isaiah 1:2-9 is late because it is retrospective and appears to be a summary of the prophet's ministry and its outcome, but Kaiser then says that it is a "prophetic oracle belonging to a previous age" (page 6), indicating that a later scribe did not create it, but used it---meaning it was earlier. Kaiser also states that the later scribe presents Isaiah 1:2-9 "as a valid interpretation of the situation in his own community, living in the expectation of the final judgment" (page 6).
On at least three occasions---on pages 19, 35-36, and 71---Kaiser attributes an oracle to the prophet Isaiah in the eighth century B.C.E. because it appears to present Judah in a state of security and prosperity. The oracles on the capitalistic or political oppression of the poor (i.e., in Isaiah 10) are dated to the eighth century, as are the passages in which God tells Judah not to be so smug, for she will experience divine wrath. I suppose that, in the exilic and the post-exilic periods, Judah was less smug, considering all that she had experienced. But Kaiser affirms on page 35 that the eighth century was a time when Judah and Israel enlarged their territories and achieved "an increase in economic prosperity".
In Isaiah 1:25-26, God promises that he will purify Jerusalem's dross and later restore her judges and the city itself. Then, vv 27-28 states that Zion and those in her who turn will be redeemed by justice and righteousness, but evildoers and those who forsake the LORD will be consumed. Kaiser believes that vv 27-28 are exilic, and that these verses affirmed even in exile that "God's promise and God's threat are still in force" (page 21), meaning that the Jews should turn to god to be restored. My problem with this is that v 27 says that "her turners"---Zion's---will be redeemed in righteousness. Are the exiles "her turners" when they do not even live in Zion?
Isaiah 2:2-5 describes the establishment of the house of the LORD, Gentiles going to Zion to learn God's ways, and peace, as destructive objects of warfare are converted into tools for agriculture. Kaiser thinks that Isaiah 2:2-5 was "interpolated in a later, probably post-exilic redaction, for the sake of [its] use in worship, so that the word spoken by the prophet in the past might be kept alive for the contemporary congregation" (page 23). On pages 29-30, Kaiser explains more what he means. He notes that Isaiah 2:2-5 comes before Isaiah's prophecies of warning, and this indicates that "this congregation lacks everything which is promised here" (page 29). Kaiser believes that Isaiah 2:2-5 was written down and "joined to the scrolls containing the genuine prophecies of Isaiah" in the post-exilic period, for the expectations of Isaiah 2:2-5 "exceed even those of [the exilic] Deutero-Isaiah" (page 19). The message of Isaiah 2:5 ("let us walk in the light of the LORD"), according to Kaiser, is that the Judahites are to walk securely in the light of the LORD, unafraid of their enemies, the same way that one walks securely under the light of the sun. The idea is that the Judahites should realize that they are still God's people, even with the exile, and they should obey the will of God. On page 25, however, Kaiser states that Isaiah 2:2-5 was used in pre-exilic worship. He doesn't believe that Isaiah or Micah (whose book has a similar oracle in Micah 4:1-4) wrote it, but that their books contain two versions of a common oracle. Kaiser argues that Isaiah 2:2-5 does not mesh with the oracles of Isaiah that are authentic, for Isaiah 2:2-5 talks about "the battle between the nations" (page 25).
In Isaiah 3:1-9, there is a prophetic description of the desolation of Judah, followed by vv 10-11, which affirm that it is well with the righteous but ill with the wicked. Kaiser states on page 40 that "In verses 9b-11, a later voice is heard in words which individualize the idea of judgment for pastoral purposes, whereas in the poem that comes from Isaiah himself, the anger of God ultimately falls upon the whole people (cf. 3.12; 5.13)." For Kaiser, the individualistic nature of vv 10-11 does not mesh with Isaiah's more communal focus.
In Isaiah 4:2-6, there is a prediction of restoration: that those left in Jerusalem will be called holy, and that the LORD will create a cloud by day and a pillar of fire by night over Mount Zion after judgment has cleansed the filth and blood-guilt of Jerusalem. Kaiser acknowledges that Isaiah himself had a sense of hope, which we see in Isaiah 7:3---where Isaiah's own son is called Shear-Yashuv, "a remnant shall return." But Kaiser thinks that Isaiah 4:2-6 breaks the rhythm of the text---and my guess is that this is because 4:1 is negative, and then 4:2 has "in that day" followed by a positive prophecy. The transition from negative to positive is not smooth, and so Isaiah 4:2-6 may have been inserted by a scribe who wanted to add a note of restoration. Kaiser says that a pre-exilic date for Isaiah 4:2-6 is reasonable, for "Verse 3 assumes that the great and purifying judgment of God has not yet begun" (page 53). But he opts for a post-exilic date---even as late as the third-early second centuries B.C.E. The setting he envisions is that the post-exilic community has just experienced exile, and yet it does not consider itself to be all that holy, and so it envisions yet another judgment. (At least that is my impression of what Kaiser is saying on page 54.) And yet, Kaiser says on page 85 that things were added to Isaiah to comfort the post-exilic community---to encourage her (after the fulfillment of Isaiah's prophecy about the exile) that she is holy and that God's promises will be fulfilled.
Isaiah 7:8-9 says that Damascus is the head of Aram and Rezin the head of Damascus---that Ephraim will be broken within 65 years and be without a people---and that Samaria is the head of Ephraim, and the son of Remaliah the head of Samaria. Kaiser thinks that the part about Ephraim being broken and without a people is awkward in the text (in that it interrupts the text's train of thought) and is thus an interpolation. He believes that the interpolation refers to an event in 671 B.C.E., when "Esar-haddon settled a foreign ruling class in Samaria" (page 94)
I want to turn now to Kaiser's argument that Assyria in certain (not all) parts of Isaiah is an allegory for the Seleucids in the third century B.C.E. Kaiser makes this claim for the first time on pages 142-143. He thinks that Isaiah 10:12 (which says that the LORD, after finishing his work on Mount Zion and in Jerusalem, will punish the arrogance of the king of Assyria) is an interpolation because it interrupts the king of Assyria's boast, which picks right back up in v 13. Although Kaiser appears to hold that Isaiah 10:5-15 is about Sargon, he says that v 12 is a "cryptic reference to the Seleucid rule" (page 143). On pages 145-146, Kaiser argues that Isaiah 10:17 is about the Seleucids. He says that v 17 does not fit into its context that well because, whereas v 16 posits a long death, v 17 says that the destruction will come in one day. Kaiser states that someone inserted v 17 in order to affirm that God would destroy the contemporary oppressors of Israel---the Seleucids---as God overthrew Israel's previous enemies, and this was to be "read in the course of worship" (page 146). Why else would somebody add that little oracle of judgment?, Kaiser appears to wonder. Regarding Isaiah 24:24-27a, Kaiser notes the references to other passages of Scripture (passages in Isaiah, the Exodus story, the Gideon story) and says that Isaiah 24:24-27a "breathes the atmosphere of a zealous study of the scripture" (page 149). He maintains that the passage was designed to prepare a remnant in the congregation to endure God's wrath---and he speculates that its setting was the time of the Seleucids, for whom the Assyrians became a "cryptic name."
On page 164, Kaiser argues that Isaiah 11:10-16 is post-exilic. It assumes a widespread Jewish diaspora, which was primarily true in the post-exilic period, especially during the time of the Diadachoi (although Kaiser acknowledges that the stage had been set for such a Diaspora since 722 for Northern Israel and 586 for Judah---and Joel 3:6 even mentions that the Philistines and Phoenicians sold people from Judah into slavery in Greek lands). According to Kaiser, v 13 is about the Samaritan schism in the third century B.C.E.. For Kaiser, the references to God's coming deliverance of Judah and her exiles from Egypt and Assyria concerns the Ptolemies (in Egypt) and the Seleucids (for whom Assyria is a code-name). (Note: v 13 just says that Judah is oppressed, and Kaiser concludes that the oppressors are Egypt and Assyria. But vv 11, 15-16 predict the return of the exiles from those two countries.) Whereas Isaiah focused on those staying behind in Judah as the remnant (Isaiah 6:13; 7:3; 10:20-22), Isaiah 11:10-16 is conscious of Diaspora Judaism---and it appears to echo Second Isaiah's prophecy of return from a foreign land (though I wonder how Kaiser would interpret the "return" part of Isaiah's son, "a remnant shall return"); consequently, it is not Isaian but came after Isaiah. And there is a prophecy about a second David---which would resonate in a time that lacked a Davidic monarch.
I want to note one more thing: Kaiser cites Isaiah 19:23f. on page 143, when he is talking about Assyria being an allegory for the Seleucids in certain passages. That passage is about the joining of Israel with Assyria and Egypt in worship. For Kaiser, is this about the unity of Jews---those in Palestine with those in the Diaspora? Or is it saying that the Seleucids and the Ptolemies will worship the true God after God judges them?
A while back, I wrote about Niels Peter Lemche's argument that Isaiah did not know about the Exodus, and that the references to the Exodus in First Isaiah are from a later hand. I learned from Kaiser at least one scholarly rationale for that point of view. I don't know whether or not Kaiser thinks that Isaiah knows about the Exodus. But he dates the references to the Exodus in Isaiah 1-12 to Israel's post-exilic period.