Heidegger's Bible Handbook: Hosea: Book of the Twelve

1. The minor Prophets are called שנים עשר, the Twelve, by the Hebrews; תריסר, the Twelve, by the Chaldeans; δωδεκαπρόφητον, the Twelvefold Prophet, by the Greeks. Whether they were conjoined into one scroll, and by whom?

The נביאים קטנים, minor Prophets, twelve in number, follow. Whence their books are simply called שנים עשר, the Twelve, by the Hebrews; תרי עסר, the Twelve, תריסר by contraction, by the Chaldeans; but δωδεκαπρόφητον, the Twelvefold Prophet, by the Greeks, as if it were one book, that is, multiple Prophets reduced to one book, lest they should be more easily lost separately, as indeed Saint Theodoret in his Proœmio de Temporibus observes; with Danæus denying the same, because Nahum calls his vision a סֵפֶר/book, Nahum 1:1. Yet that no more argues a separation than the title of Matthew, the book of the generation, Matthew 1:1, argues a separation of the first chapter from the rest. Certainly also in Matthew 2:5 and Acts 7:42 it is called the βίβλος προφητῶν, book of the prophets (as if one). That they were gathered into one scroll by the College of the Prophets, the Most Learned Ursinus attempts to prove, Analectis, part 2, Book IV, section 10.