Conceptually, the tradition of escape from Egypt requires a place to go, a happy ending. Numbers 21 and Deuteronomy 2–3 provide this in the east, in a tradition that does not of itself assume combination with a western campaign. The Bible as we now have it provides the book of Joshua, with its crossing of the Jordan River from the east (chapters 3–4), the assault on Jericho (chapter 6), followed by eventual victory at Ai (chapters 7–8), forced compromise with the Gibeonites (chapter 9), and at last a sweeping success against the assembled forces of first the south, then the north (chapters 10–11). The rest of the book is built around detailed territorial definitions for all the tribes, both east and west of the Jordan (chapters 13–19), with special consideration for the Levites (chapter 21). All this is framed by speeches from Joshua himself in chapters 1 and 23, which have long been understood as classic examples of deuteronomistic work, in making this collection part of a larger history.

Although the western conquest led by Joshua depends in its full expression on the old Israelite tradition of exodus from Egypt, the book gives it a limited and finally Judahite perspective. Like the later revisions of the Moses traditions, which integrate the tribal scheme of Genesis into the old tales of departure and invasion, the book of Joshua pictures a conquest by twelve tribes. Perhaps this tribal focus allows Judah to be given a special role; in any case, the establishment of all Israel, far beyond the borders of Judah, is essential. Moreover, the geographical ambitions of the book are considerable, reaching beyond the proven accomplishment of Israel in any period. Joshua mixes an Israelite ideal with an overwhelmingly Judahite realization. For all the narrative located in the territory of Israel, it is extremely difficult to isolate plausibly Israelite material. In the end, the one most convincing text is the account of Joshua's victory at Ai in chapter 8. This alone provides a starting point for understanding the construction of a western conquest from the tradition of Joshua as ancient warrior leader. Joshua 8 belongs to the family of biblical texts that presents Israel as a collective unit, especially for going to war, and as such, the text belongs with the various Moses materials.