So, when
was the canon of the Hebrew Bible closed?
In 1871 Heinrich Graetz, drawing on Mishnaic and Talmudic sources, theorised that there must have been a late first century Council of Jamnia or Council of Yavne at which the canon of the Hebrew Bible was finalised. The concept is a hypothesis to explain the canonisation of the Writings (the third division of the Hebrew Bible) resulting in the closing of the Hebrew canon[1]. This view became the prevailing scholarly consensus for much of the 20th century. However, later scholars noted that none of the sources actually mentioned books that had been withdrawn from a canon, and questioned the whole premise that the discussions were about canonicity at all, asserting that they were actually dealing with other concerns entirely. Jacob Neusner published books in 1987 and 1988 arguing that the "notion of Torah" was expanded in the second century CE to include a variety of other works. He argued for an extension of the Torah in the second century CE, after the destruction of the Jerusalem in 70 CE and the end of Second Temple Judaism.
In general, there is no scholarly consensus as to when the Jewish canon was set, and the Council of Yavne/Jamnia (90CE) is no longer thought to be the occasion for the closure of the canon. Perhaps there was no specific date. However, the emergence of supplements to the Torah such as the Mishnah or Oral Law suggests that the canon was certainly closed by the second century BCE.
What emerged from this era included a rejection of the Septuagint as the authoritative text along with the books included in many manuscripts which were thought to not exist in Hebrew or Aramaic, or, alternatively, were considered to be written after the time of Ezra. However, the Book of Daniel, included in the Jewish canon, was not written until 165 BC – some 300 years after the death of Ezra - and several books that were excluded have since been discovered in ancient manuscripts of the original Hebrew or Aramaic amongst the Dead Sea Scrolls, and yet others, such as 1 Maccabees, are considered by the unanimous consent of modern and many ancient scholars to have been authored in Hebrew. These books, included in Septuagint manuscripts but excluded in later Hebrew texts, are the deuterocanonical books of Catholicism and Eastern Orthodoxy. Some of the books not admitted into the Hebrew canon, such as the Wisdom of Solomon and 2 Maccabees (originally Greek compositions) gave the only textual support for the common first century Jewish belief in the after-life. By whatever means, the canon of the Hebrew Bible was fixed by the second century CE. Otherwise we would not need the Talmud and other sources to supplement it by the use of other documents.
Sociologically, these developments achieved two important ends, namely, the preservation of the Hebrew language, at least for religious use (even among the diaspora), and possibly the final separation and distinction between the Jewish and Christian communities, although the separation is more complex than just a single event. The Bible we have today is not the Bible of the early Jews. The Septuagint was their Bible and every translation since then constitutes a separate interpretation.
[1] Jack P. Lewis, The Anchor Bible Dictionary Vol. III, pp. 634–7 (New York 1992)