Joshua 24:26 - Ellicott's Commentary On The Whole Bible

And Joshua wrote these words in the book of the law of God. — Primarily “these words” appear to refer to the transaction just recorded. But it must be observed that this is also the second signature among the sacred writers of the Old Testament. The first is that of Moses, in Deuteronomy 31:9 : “Moses wrote this law, and delivered it unto the priests,” &c. The next signature after Joshua’s is that of Samuel (1 Samuel 10:25): “Samuel told the people the manner of the kingdom, and wrote it in the [not a] book, and laid it up before the Lord.” We have here a clue to the authorship of the Old Testament, and to the view of the writers who succeeded Moses in what they did. They did not look upon themselves as writers of distinct books, but as authorised to add their part to the book already written, to write what was assigned to them “in the book of the law of God.” The unity of Holy Scripture is thus seen to have been an essential feature of the Bible from the very first.