History of ancient Israel and Judah
2 Esdras 14:45-46, which was written in the second century CE, declares: "Make public the twenty-four books that you wrote first, and let the worthy and the unworthy read them; but keep the seventy that were written last, in order to give them to the wise among your people."  This is the first known reference to the canonized Hebrew Bible, and the seventy non-canonical texts may have been mystical; the Talmud suggests other mystical traditions which may have their roots in Second Temple Judaism.