What makes the Bible unique among all religious books, according to this teaching?
Scripture is unique because every word of it came through the nation of Israel. All its writers were Jews, and, as Paul explains in Romans 3, unto the Jews were committed the oracles—the Word—of God. That divine origin through Israel distinguishes it from every other religious book.
Les teaches that everything has to come through this one little nation, Israel, and that every word of this Book came out of the nation of Israel. He notes that all the writers of Scripture were Jews, and Paul makes this plain in Romans chapter 3: what advantage then hath the Jew? Much in every way, but chiefly that unto them were committed the oracles or the Word of God. Les says this is what makes this Book totally unique from any other religious book on this planet. This point is tied to the Abrahamic Covenant, where God promised that in Abraham's seed all the nations of the earth would be blessed.