In 2 Esdras 14:37-48, the story is told of Ezra's restoration of the Tanakh
37 I took the five men, as he had commanded me, and we went out into the field and remained there. 38 So it happened to me on the next day that a voice called me: “Ezra, open your mouth and drink what I give you to drink.” 39 So I opened my mouth, and a full cup was set before me. It was full of something like water, but its color was like fire. 40 I took it and drank, and when I had drunk it my heart poured forth understanding, and wisdom increased in my heart, for my spirit retained memory. 41 My mouth was opened and wasn’t shut anymore. 42 The Most High, moreover, gave understanding to the five men, and they wrote in turns what was dictated, in characters that they didn’t know, and they sat for forty days. They wrote by day, 43 but by night they ate bread; however, I spoke by day and wasn’t silent by night. 44 Ninety-four scrolls were written in the forty days. 45 Then when the forty days were completed, the Most High said to me, “Make public the ones you wrote first so that the worthy and unworthy may read them. 46 But keep the last seventy so that you may transmit them to the wise among your people. 47 In these are the fountains of understanding, the source of wisdom, and the river of knowledge.” 48 And so I did.
Most scholars agree that the first twenty-four scrolls refer to the twenty-four books in the Jewish canon of the Tanakh.
However, Wikipedia states that the "last seventy" scrolls could refer to refer to the Septuagint, most of the apocrypha, or the lost books that are described in the Bible.
I am wondering if any of the Jewish users here can help in explaining this mysterious passage and what it most likely refers to.