The Book of Isaiah (Hebrew: ספר ישעיהו, IPA: [sɛ.fɛr jə.ʃaʕ.ˈjɑː.hu]) is the first of the Latter Prophets in the Hebrew Bible and the first of the Major Prophets in the Christian Old Testament. It is identified by a superscription as the words of the 8th-century BCE prophet Isaiah ben Amoz, but there is extensive evidence that much of it was composed during the Babylonian captivity and later. Bernhard Duhm originated the view, held as a consensus through most of the 20th century, that the book comprises three separate collections of oracles:[ Proto-Isaiah (chapters 1–39), containing the words of Isaiah; Deutero-Isaiah (chapters 40–55), the work of an anonymous 6th-century BCE author writing during the Exile; and Trito-Isaiah (chapters 56–66), composed after the return from Exile. While virtually no scholars today attribute the entire book, or even most of it, to one person, the book's essential unity has become a focus in current research. Isaiah 1–33 promises judgment and restoration for Judah, Jerusalem and the nations, and chapters 34–66 presume that judgment has been pronounced and restoration follows soon. It can thus be read as an extended meditation on the destiny of Jerusalem into and after the Exile.
The scholarly consensus which held sway through most of the 20th century saw three separate collections of oracles in the book of Isaiah. A typical outline based on this understanding of the book sees its underlying structure in terms of the identification of historical figures who might have been their authors:
1–39: Proto-Isaiah, containing the words of the original Isaiah;
40–55: Deutero-Isaiah, the work of an anonymous Exilic author;
56–66: Trito-Isaiah, an anthology of about twelve passages.
While one part of the consensus still holds – virtually no contemporary scholar maintains that the entire book, or even most of it, was written by one person – this perception of Isaiah as made up of three rather distinct sections underwent a radical challenge in the last quarter of the 20th century. The newer approach looks at the book in terms of its literary and formal characteristics, rather than authors, and sees in it a two-part structure divided between chapters 33 and 34:
1–33: Warnings of judgment and promises of subsequent restoration for Jerusalem, Judah and the nations;
34–66: Judgment has already taken place and restoration is at hand.
The book opens by setting out the themes of judgment and subsequent restoration for the righteous. God has a plan which will be realised on the "Day of Yahweh", when Jerusalem will become the centre of his worldwide rule. On that day all the nations of the world will come to Zion (Jerusalem) for instruction, but first the city must be punished and cleansed of evil. Israel is invited to join in this plan. Chapters 5–12 explain the significance of the Assyrian judgment against Israel: righteous rule by the Davidic king will follow after the arrogant Assyrian monarch is brought down. Chapters 13–27 announce the preparation of the nations for Yahweh's world rule; chapters 28–33 announce that a royal saviour (a messiah) will emerge in the aftermath of Jerusalem's punishment and the destruction of her oppressor.
The oppressor (now identified as Babylon rather than Assyria) is about to fall. Chapters 34–35 tell how Yahweh will return the redeemed exiles to Jerusalem. Chapters 36–39 tell of the faithfulness of king Hezekiah to Yahweh during the Assyrian siege as a model for the restored community. Chapters 40–54 state that the restoration of Zion is taking place because Yahweh, the creator of the universe, has designated the Persian king Cyrus the Great as the promised messiah and temple-builder. Chapters 55–66 are an exhortation to Israel to keep the covenant. God's eternal promise to David is now made to the people of Israel/Judah at large. The book ends by enjoining righteousness as the final stages of God's plan come to pass, including the pilgrimage of the nations to Zion and the realisation of Yahweh's kingship.
The older understanding of this book as three fairly discrete sections attributable to identifiable authors leads to a more atomised picture of its contents, as in this example:
Proto-Isaiah/First Isaiah (chapters 1–39):
1–12: Oracles against Judah mostly from Isaiah's early years;
13–23: Oracles against foreign nations from his middle years;
24–27: The "Isaiah Apocalypse", added at a much later date;
28–33: Oracles from Isaiah's later ministry
34–35: A vision of Zion, perhaps a later addition;
36–39: Stories of Isaiah's life, some from the Book of Kings
Deutero-Isaiah/Second Isaiah (chapters 40–54), with two major divisions, 40–48 and 49–54, the first emphasising Israel, the second Zion and Jerusalem:
An introduction and conclusion stressing the power of God's word over everything;
A second introduction and conclusion within these in which a herald announces salvation to Jerusalem;
Fragments of hymns dividing various sections;
The role of foreign nations, the fall of Babylon, and the rise of Cyrus as God's chosen one;
Four "Servant Songs" personalising the message of the prophet;
Several longer poems on topics such as God's power and invitations to Israel to trust in him;
Trito-Isaiah/Third Isaiah (chapters 55–66):
A collection of oracles by unknown prophets in the years immediately after the return from Babylon