"Hidden things," "mysterious or esoteric lore," "secret knowledge accessible only to an inner circle of believers"—all these expressions have been used to describe the Old and New Testament Apocrypha. Yet although there's been considerable interest in these books over the centuries, they haven't ultimately passed the test of "Scripture." They've been found wanting and so haven't been included in the Old or New Testament canon.
Some of these Apocryphal books contain interesting historical material. Others resemble the wisdom literature of the Old Testament. And others read more like fables. Today some Bible translations do contain selections from the Apocryphal writings. But many people don't accept them as canon. They feel these books simply haven't proved themselves—in the way the accepted books of the Bible have—to be the Word of God.
One of the books in the Old Testament Apocrypha, II Esdras (another name for Ezra), explains the tradition behind the Apocrypha. In this book, Ezra relates how God spoke to him out of a bush and told him to write down words of understanding that He would give him.