Almost all the early Christian canonical lists of OT books limited the number to 22, which more or less equals the modern Protestant reckoning of 39 books. For how 22 = 39, see this good handout prepared by Tyler Williams and follow these steps: (1) start with the Protestant canon of 39 books; (2) note that it contains the same books as the Jewish canon of 24 books, just arranged differently; (3) using the Jewish canon of 24 books, count Lamentations with Jeremiah and Ruth with Judges; (4) notice that you now have 22 books.
The number 22 is first attested in Josephus (CA 1.37–41), although R.H. Charles argued for its presence already in Jubilees about 2 ½ centuries earlier (see his The Book of Jubilees, 1902; also see the criticism by James VanderKam, From Revelation to Canon, 2000, pp. 18–19). I should note that Josephus does not tell us which books he includes, leaving scholars to debate whether his 22 books equals what Christians later called the 22 books.
The Hebrew alphabet has 22 letters, and the Fathers often saw a connection between the 22 letters that serve as an introduction to learning and the 22 books that serve as an introduction to piety. The connection between the OT and the Hebrew alphabet is first attested in Origen’s commentary on the first Psalm (preserved by Eusebius, HE 6.25).
It is possible that Origen learned of this connection from a Jewish source, though he does not say so. The Jewish sources other than Josephus unanimously (as far as I know) count their books as 24, and this number is attested almost as early as Josephus’s 22, being found already in 4 Ezra 14:45 and the Gospel of Thomas 52. The number 24 is also assumed in the famous passage from the Babylonian Talmud, Baba Bathra 14b. Again, the 24 books are the same as the 22 books, just counted differently.
While the early Fathers usually limited the OT to 22 books, and thus the books of the Jewish canon, two caveats should be kept in mind. (1) The Greek form of the book sometimes differed radically from the Hebrew/Jewish form. This is apparent especially in, e.g., the Book of Jeremiah, which almost always in Christian reckoning included Lamentations, Baruch, and the Letter of Jeremiah, the latter two being completely absent from the Jewish Bible, the first being present but not counted with Jeremiah. Of course, the Book of Jeremiah itself is quite different in its Hebrew and Greek forms. Other obvious examples would be Daniel and Esther, less obvious examples abound.
(2) Even Fathers that seem to limit their OT canon to the Jewish Bible sometimes limit it even more, excluding the book of Esther. Those that omit Esther include Melito, Athanasius, Gregory of Nazianzus, and Amphilochus. Athanasius includes Esther as one of the “other books” to be read but not used for doctrine. Amphilochus appends a note to his list saying that some people include Esther.
Those Fathers who mention a connection between the number of OT books and the letters of the Hebrew alphabet include:
- Origen, as cited above. (Though I agree with Dominique Barthélemy that the canon list Origen gives does not represent his own OT canon, but merely that of the “Hebrews”; see Études d’histoire du texte de l’Ancien Testament, 1978, p. 114.)
- Athanasius of Alexandria in his 39th Festal Letter.
- Epiphanius of Salamis in three separate lists: Panarion 8.6.1-4; De mens. et pond. 4; 22-23. In each of these lists, Epiphanius mentions also the number 27, which is simply a different way of counting the 22 books, in accordance with the five doubled letters of the Hebrew alphabet which bring the number of Hebrew letters to 27. Jerome also mentions the number 27 and the five doubled letters/books (Prologus Galeatus).
- Gregory of Nazianzus, Carmen 1.12.
- Hilary of Poitiers, Tractatus super Psalmos 15. (See here)
- Jerome, Prologus Galeatus.
Those that obviously count 22 OT books, but do not mention the alphabet include:
- Cyril of Jerusalem (Catechetical Lecture 4.35), who stresses the number 22 for the OT books, but does not mention the alphabet.
- The Council of Laodicea, canon 60. Two notes: (1) Though the total number of books is not given, each book is assigned a number, with the last book, Daniel, being given number 22. (2) It is not certain that this list originated with the council, or whether it was added later.
- Rufinus of Aquileia, Commentary on the Apostle's Creed, 37. Notes: it is clear that Rufinus is aiming for the number 22 because he counts Ruth with Judges, and reports that the Hebrews count the four books of Kings (i.e. our Samuel and Kings) as two, etc. The only reason to do this is to preserve the number 22. I am aware of Meinrad Stenzel’s objection to this view (“Der Bibelkanon des Rufin von Aquileja,” Biblica 23 (1942): 43–61 (45)), but I find his argument unpersuasive.
Some canon lists contain only the books accepted by the Jews (with allowance for variations between the Greek and Hebrew forms of those books), but do not seem to count them as 22. These include:
- Melito of Sardis (preserved in Eusebius, HE 4.26). I assume with Albert Sundberg that Melito does not include the Wisdom of Solomon (see The Old Testament of the Early Church (Cambridge, MA: Harvard, 1964), 133–134 n. 10). Some scholars have attempted to count Melito’s books as 22 (e.g. Sundberg, 133–134), but others more simply count 25 (e.g. R.T. Beckwith, The Old Testament Canon of the New Testament Church, 1985, 184–185).
- Hierosolymitanus 54 (= the Bryennios list), a list of OT canonical books found in the same manuscript which yielded the Didache. The manuscript was discovered in Jerusalem (hence Hierosolymitanus) by Philotheos Bryennios. The list counts 27 books, which is reminiscent of Epiphanius (see above). This canon list was studied by J.-P. Audet, “A Hebrew-Aramaic List of Books of the Old Testament in Greek Transcription,” JThS 1 (1950): 135–154; reprinted in S.Z. Leiman (ed.), Canon and Masorah of the Hebrew Bible, 1974, 52–71.
- Amphilochus of Iconium, Iambi ad Seleucum 251–319. Amphilocus may count 22 books, but he does not say, nor does he assign numbers to the individual books.
- The Apostolic Canons, canon 85. I follow the text of P.-P. Joannou, Discipline générale antique, 3 vols., Fonti codificazione canonica orientale 9 (Grottaferrata (Rome): Tipografia Italo-Orientale “S. Nilo,” 1961–64), 1.2.51–52. The text of F.X. Funk includes after Eshter, “Judith and three books of Maccabees,” which is an interpolation from the Latin (Didascalia Constitutiones Apostolorum, 2 vols. (Paderborn: Schoeningh, 1905), 1.590–592).
Some late 4th-century Latin lists incorporate the “Apocrypha” (as they are called by Protestants; “deuterocanonicals” among Roman Catholics; “ecclesiastical books” according to Rufinus, in the work cited above, section 38). Thus, they include more books than any of those mentioned already. These longer lists include:
- The Mommsen Catalogue (= the Cheltenham List, from North Africa ca. 359).
- Council of Hippo in 393, the canons of which were not preserved, but the scriptural canon was reaffirmed at Carthage in 397.
- Council of Carthage in 397, canon 26.
- Augustine’s list in On Christian Doctrine 2.13.
- The list of Pope Innocent I given in his letter to Exsuperius, section 7. This list actually comes from the early 5th century (ca. 405), and is the first pronouncement of Rome on the issue.
Each of these five sources (except, perhaps, the Mommsen Catalogue) provides a list including the same six books rejected by the Jews: Wisdom of Solomon, Sirach, Tobit, Judith, and 1 and 2 Maccabees. While the Mommsen Catalogue does list the latter four books, it is uncertain whether its title “Salomonis” includes Wisdom and Sirach, though the given stichometry makes this probable. See T. Zahn, Geschichte des neutestamentlichen Kanons, 2 vols. (1888–92; repr. New York: Georg Olms, 1975), 2.151. These 6 “deuterocanonical“ books are the same as those listed by Jerome (Preaf. in lib. Sal.) and Rufinus (see citation above) as books to be read, but not for the confirmation of doctrine. Athanasius included a similar list of “books to be read” outside the canon, but his list omits reference to the Maccabees, and includes Esther.
Now I have something on this blog to show for the month of June.