Deuteronomy is the only book of the Torah delivered almost entirely in the first person by a human speaker. Moses stands on the plains of Moab, in sight of a land he has been told he will not enter, and speaks. The frame is a farewell, and it gives the book a rhetorical intensity the four preceding books do not have: it argues, pleads, remembers and warns rather than narrating.
The material inside the frame is a full legal corpus. Chapters 12 to 26 set out laws of worship, courts, kingship, warfare, debt, marriage and property, and they open with a demand that has consequences for everything after it. Sacrifice is to happen at the place the Lord will choose, and nowhere else. The local altars that the earlier books take for granted are to be destroyed. That single requirement reorganises Israelite religion around one sanctuary and forces the book to legislate for everything the local shrines used to handle, including what a Levite without a shrine is now to live on.
Chapter 6 carries the Shema, hear O Israel, which became the central declaration of Jewish liturgy and is recited twice daily. Chapter 28 sets blessings against curses at length, and the curses run far longer. Chapter 34 records the death of Moses and the fact that no one knows his burial place, a passage that plainly cannot be his own writing and that ancient commentators already had to explain.
The shape of the whole, a historical prologue followed by stipulations, witnesses, blessings and curses, closely resembles the vassal treaties of the ancient Near East, and the resemblance is not thought to be coincidence.