2 Esdras 14:45-47
It came to pass, when the forty days were fulfilled, that the Most High spoke to me, saying, “The first books that you have written, publish openly, and let the worthy and unworthy read them; but keep the last seventy, that you may deliver them to those who are wise among your people; for in them is the spring of understanding, the fountain of wisdom, and the stream of knowledge.”