Rebuttal — One Voice

The unity-of-Isaiah response begins where the previous section ended: with the hypothesis fairly stated. It does not strawman. It answers four pillars with four answers, and grounds the whole in the witness of Christ.

First — to the named figure of Cyrus (44:28, 45:1). The critical reading treats Cyrus's naming as evidence of late composition. But the Old Testament records other instances where prophets name future figures generations in advance. 1 Kings 13:2 — about three centuries before his reign — names King Josiah explicitly. If the principle of predictive naming is admitted there (and it must be, on any conservative reading of canon), it cannot be ruled out at Isaiah 44 a priori.

Second — to the shift of setting. The critical reading takes the chapter-40 horizon as evidence of an exilic author. But the prophets habitually project themselves into future settings to address future generations; Jeremiah's seventy-years prophecy (Jer 25:11) anticipates the same exile. Isaiah's eighth-century announcement of a sixth-century captivity (39:6–7) and the comfort that follows is a structural feature of his prophetic ministry, not an authorial seam.

Third — to vocabulary and style. The phrase 'the Holy One of Israel' — once thought distinctive of Deutero-Isaiah — actually appears in nearly equal density across both halves (twelve times in 1–39, fourteen times in 40–66). The most distinctive Isaianic phrase binds the book together rather than splitting it.

Fourth — to manuscript evidence. The Great Isaiah Scroll, 1QIsa-a, dates to ~125 BC. It contains the entire book. There is no scribal mark, no break, no division between Isaiah 39 and Isaiah 40. The pre-Christian Hebrew witness treats the book as one. (See the visual on this page.)

Fifth and decisive — the witness of Christ (see the previous section). The Lord Jesus quotes both halves and attributes both to 'the prophet Isaiah.' For Christian faith, this is not one consideration among many; it is the determining one. The critical hypothesis can be entertained as a literary-historical proposal; it cannot be made dogmatic without revising what Christ taught about who wrote the book.

Finally — patristic and rabbinic tradition consistently ascribes the entire book to one Isaiah. Sirach 48:22–25 (second-century BC) treats it as one work. Josephus reads it as one. The whole pre-modern tradition is a single voice on this point.