In the Hebrew Bible the Book of Daniel stands, not as in our Bible among the Prophets, after Ezekiel, but among the miscellaneous books in the third division, the "Scriptures." Various reasons have been suggested for this, but by far the most probable is that at the time when Daniel became current, in the second century B.C., the Prophets were already a definite group of writings with a traditional use in the readings of the Synagogue, to which a new book could not well be added.
The Book of Daniel consists of two parts, stories about Daniel and his three comrades (cc. 1-6), and visions of Daniel (cc. 7-12); in the latter Daniel reports his visions in the first person as Ezekiel habitually does, and it was only natural that he should be taken for the author of the book.
According to the introduction to the first story, Daniel and his three friends, Hananiah, Mishael, and Azariah, were Jewish youths of high birth who were carried captive to Babylon by Nebuchadnezzar in the first deportation (which is erroneously dated in the third year of Jehoiakim). One story (Dan. 1) tells how these youths contrived to avoid all danger of eating unclean food, and how God blessed them in body and mind for their scrupulousness in observance of the dietary laws; another (c. 3), how the three were saved from Nebuchadnezzar's overheated furnace, into which they were thrown for refusing to worship the idol; a third (c. 6), how Daniel was cast into the lions' den for praying to his God despite the edict of Darius. These miraculous deliverances constrain the heathen kings publicly to acknowledge that the God of the Jews is the greatest of gods. The same acknowledgment is drawn from Nebuchadnezzar when Daniel recalls his forgotten dream and interprets it, after all the diviners of Babylon had failed (c. 2); he alone is able to decipher and explain for Belshazzar the handwriting on the wall (c. 5). The stories of Nebuchadnezzar's madness (c. 2) and of Belshazzar's feast (c. 5) teach also how God punishes kings who in their pride of power exalt themselves before him, or in their arrogance profane his holy things.
All of them thus magnify the God of the Jews as in power and wisdom above all other gods, and two of the most striking of them have for their theme the deliverance from mortal peril of men who stood faithful to their religion against the king's commandment. These obvious motives, as we shall presently see, have a bearing on the age of the stories.