new heavens and a new earth, and the key role of Jerusalem and the Messiah. But now that we have clarified the book’s structure we are in a position to go further and ask how the various aspects of its message relate to one another. Jerusalem Part 1 1–12 Part 2 13–27 Assyria Part 3 28–35 Part 4 36–39 - - - Part 5 40:1–51:11 Part 6 51:12–55:13 Babylon New Jerusalem Part 7 56–66 Of key significance here are the two passages, in chapters 6 and 40, in which Isaiah finds himself summoned