Whitaker adduces the evidence of Josephus (as evidence for the Jewish church before Christ, even though he lived after Christ), and Jerome, as another church father after Christ, who both rejected all the deutero-canonical books (pp. 60-61 of Whitaker). Jerome, as is well-known, denied the canonicity of the deutero-canonical books. By the way, Jerome is listed not only as a saint of the Roman Catholic church, but also as one of its doctors. Apparently, one of the doctors of the church denies that the church should receive Maccabees, Baruch, Sirach, etc. These are his actual words:
As, then, there are twenty-two elementary characters by means of which we write in Hebrew all we say, and the human voice is comprehended within their limits, so we reckon twenty-two books, by which, as by the alphabet of the doctrine of God, a righteous man is instructed in tender infancy, and, as it were, while still at the breast.
The translation is from this website, and the words come from his preface to the book of Samuel in the Vulgate (in the now-standard Deutsche Bibelgesellschaft edition, the words occur on p. 364). Lest anyone doubt his meaning, he goes on to list with exactitude the books of the canon, and he explicitly says that Wisdom, Sirach, Judith, Tobit, and Shepherd are not canonical (non sunt in canone, see p. 365). Although stating that 1 Maccabees can be found in Hebrew, he does not translate it, and his mention of it occurs in the paragraph discussing books that are not in the canon.
So, once again, we have the problem of which tradition to believe. Even the fountain of the Vulgate, Jerome himself, did not believe that the deutero-canonical books were canonical. So why would it be heretical to believe Jerome today?
Josephus is a strong testimony to the Jewish church’s rejection of the deutero-canonical books. In his Against Apion, book 1, chapter 8, he says this (quoting from the Loeb translation, p. 179):
We do not possess myriads of inconsistent books, conflicting with each other. Our books, those which are justly accredited, are but two and twenty, and contain the record of all time. Of these, five are the books of Moses, comprising the laws and the traditional history from the birth of man down to the death of the lawgiver. This period falls only a little short of three thousand years. From the death of Moses until Artaxerxes, who succeeded Xerxes as king of Persia, the prophets subsequent to Moses wrote the history of the events of their own times in thirteen books. The remaining four books contain hymns to God and precepts for the conduct of human life.
Now, why would a Jew’s testimony be helpful here? Because, and simply, if the Jews rejected the deutero-canonical books, then the Roman Catholic church does not have fundamental continuity with the Old Testament church on the matter of canon, whereas the Protestant position most certainly does. The Protestants are the traditional church here!