"Four views have been proposed concerning the extent of this Book: 1. a collection of legal materials, 2. the priestly laws of Exodus and Leviticus, 3. the laws of Deuteronomy, 4. the Pentateuch. Surely Ezra could have brought back with him the Torah, i.e., the entire Pentateuch." (THE NIV STUDY BIBLE NOTES, Nehemiah 8:1)