Forming, as it does, an integral portion of the third chapter of the Greek Daniel, the principal MSS. give the Song, in that place, no independent title. It falls of course under the general title of the whole Book, Daniel.
Van Ess in his LXX (Lips.1835) entitles it Proseuche Azariou kai humnos ton trion, but as he puts this heading in curved brackets it is possibly merely his own insertion. B' is the codex which he is professing to follow in his text; but that MS. is credited with no such title in Dr. Swete's Greek Old Testament; nor do Holmes and Parsons shew any knowledge of it as existing in any of their MSS.
In the Veronese Graeco-Latin Psalter it is headed 'Humnos ton pateron hemon, and in the Turin Psalter Humnos ton trion paidon, which title it inserts again at v.57, strangely regarding that verse as the commencement of a fresh canticle with a new number, ib'. Churton (Uncan. and Apocr. Script., p.391) suggests that the former title "may have been wrongly transferred from Eccles. xliv." at the head of which it stands. He also calls it the title in the Alexandrian Psalter -- the Odes, presumably that is, at the end. But the title to Eccles. xliv. is simply pateron humnos, so that the likelihood of the transfer, deemed possible by Churton, having taken place is very small.
In the Odes, at the end of Cod. A, two canticles are extracted from this piece; the first (Ode IX.) entitled Proseuche Azariou, the second (Ode X.) Humnos ton pateron hemon, each corresponding with the name given to it. In the office of Eastern Lauds the two parts have separate titles, being assigned to different days of the week (D.C.A. art. Canticle).
In the Syriac and Arabic versions of Daniel a separate title is given after v.23 of chap. iii., and in the latter after v.52, according to Churton in his marginal notes. He also says that "the prayer of the companions of Ananias" is the Syriac title. The titles on the whole are fairly suited to their purpose; but the use of the word "children" (paidon) in the common heading of the Song contemplates the three as of the age indicated in Daniel i, rather than that in Daniel iii.
Obviously this is not meant for an independent work, since it has no proper commencement of its own. "And they walked" is clearly intended as a continuation of some foregoing history. Accordingly, its position in the LXX, Theodotion, Vulgate, and other versions, is immediately after the 23rd verse of Daniel iii., thus forming a portion of that chapter. This is clearly its natural and appropriate place. It unites well both at the beginning and the end with the canonical text, "Qui se trouve entrelassée (sic) dans le texte," as D. Martin says in the heading of the book in his French version. T. H. Horne, however (Introd.1856, II.936), mentions its "abrupt nature" as a reason for thinking that the translator did not invent it, but made use of already existing materials. But the abruptness is not so apparent to other eyes and ears. Indeed G. Jahn, in his note on Dan. iii.24 (Leipzig, 1904), considers the gap between vv.23 and 24 in the Massoretic text is filled up satisfactorily in the LXX and Theodotion only.
By means of this insertion, and the inclusion of what in A.V. are the first four verses of chap. iv., this chapter is lengthened out in the Greek and Latin versions to exactly 100 verses.
Bishop Gray's note (Key to O. T.1797, p.608), in which he says "the Song of the three holy children is not in the Vat. copy of the LXX," is certainly a mistake. It is just possible, however, that he may have meant that the true LXX version was absent from it. So Ball somewhat obscurely (p.310 "the Alex. MS. omits"  ), and Bissell (p.442), though not very distinctly, suggest a like idea as to its omission from Dan. iii. in A, and Zöckler in his commentary falls into the same mistake (Munich, 1891, p.231). It is not unlikely that these writers successively influenced each other.
E. Philippe's idea (Vigouroux, Dict. II.1267a), that this piece was separated from the original book because "elle retarde le récit et est en dehors du but final" seems unconvincing -- as much so as Dereser's (quoted in Bissell, p.444), from whom perhaps it was borrowed -- that "the Sanhedrim at Jerusalem shortened it for convenient use." An equally unsatisfying "reason" is that of H. Deane in Daniel, his Life and Times, p.70 (pref.1888). "There is no doubt as to the antiquity of this addition, but probably on account of the feelings of hatred the three children express with regard to their enemies, it was not universally received by the Church." In the face of many stronger expressions in the O.T. received without hesitation, this explanation seems untenable, or at least insufficient. And the same may be said of G. Jahn's theory that some mention of the singing of the three, contained in the original, was expunged by the Massoretes as too wonderful and apocryphal.
Much has been made of the omission of this and the other additions from the original Syriac (e.g. Westcott, quoting Polychronius, Smith's D. B., ed.2.713b, Bissell, 448), but they are contained in the Syriac text of Origen's Hexapla, in the MS. in the Ambrosian Library at Milan (Kautzsch, I.172), published in facsimile by Ceriani. Bugati in his edition of Daniel gives this Syriac and the LXX text in parallel columns. In Jephet Ibn Ali's (the Karaite's) Arabic commentary on Daniel, translated by D. S. Margoliouth (Oxf.1889), no notice is taken of the additions. The commentary was probably written about a.d.1000.
Professor Rothstein (Kautzsch, I.173) compares the situation of the prayer in ix.4 sqq., which he deems, like this one, to have been perhaps a later insertion into the book.
It is beyond question that if this psalm of prayer and praise is to find a place anywhere in the Book of Daniel, no more suitable position can be found for it than that which it occupies so well in the Greek. If it is a digression from the course of the original narrative it is very happily placed, since it accounts satisfactorily for the statement "the king was astonied" in v.24 (91). He was surprised at the voice of praise, instead of the shrieks of pain which he had expected to produce by the execution of his decree.
In the Greek of neither O' nor Th is there variation sufficient to prove that the writer differed from the one who translated the rest of the book. Rather do the indications point to the same hand having been at work throughout. Comely says of this and its companion pieces, "Neque in trium pericoparum argumentis quidquam invenitur quo illas Danielis auctori attribuere prohibeamur" (Compendium, Paris, 1889, p.421). This, like other R. C. writings, holds of course a brief for their canonicity.
The Prayer, on the surface, claims to be by Azarias; the Song by all the three. The introductory and intermediate narrative verses are given as if from the same pen as the rest of Daniel's history; v.4 (27) reminds us in its terms of Daniel iv.37 (34) very strongly, and, in part, of ix.14. In v.24 (47) the mention of 49 (7 x 7) is paralleled by the symbolic use of the number 7 in iv.25, etc. But even if, as is likely, they did not originate with the ostensible utterers, still it is quite possible that the hand for the prayer, the narrative, and the Song may not, in the first instance, have been identical.
Probably, however, we are intended, by the producer of the piece in its present shape, to understand that the prayer and the Song are recorded, even if not originated, by the author of the whole book. If not genuine parts of Daniel, their parentage has not been assigned to any named author; and the work must be treated as anonymous, for no clue has been traced which points to a definite writer.
The putting forward in v.2 (25) of the second person of the trio, not otherwise distinguished from his fellows, is remarkable, and not suggestive of a forgery. There is nothing to shew why he led the prayer, as no special characteristics are attached to Abed-nego in our knowledge. Most likely a forger would have put the prayer into the mouth of Shadrach (Ananias), who always stands first, though the order of the last two is reversed in the one place in which the three are named in the uncanonical portion of the chapter. Ewald (Hist. of Israel, E. Tr. Lond.1874, V.486) thinks that Azarias is introduced as the eldest, or perhaps the teacher, of the other two; but this conjecture does not account for the varying orders of the names of the three in v.65.
However thick a veil may rest over the author's name, it may safely be regarded as certain that he was a Jew, and a Jew who was well acquainted with the Psalter. But the opinion as to whether he was of Babylonian, Palestinian, or Alexandrian extraction will depend in a great measure on the view taken as to the original language, whether Chaldee, Hebrew, or Greek. Professor Rothstein (p.174) admits the possibility of this addition having been made to Daniel before its translation into Greek. But Dean W. R. W. Stephens (Helps to Study of P. B., Oxf. n. d., prob.1901, p.45) may be taken as representing what has been the commonest view. He thinks it "probably composed by an Alexandrine Jew." On the other hand, Dr. Streane's remark tells against this increase of contents having begun at Alexandria. "The tendency to diffuseness, characteristic of later Judaism . . . operated much more slightly among Egyptian Jews than with their brethren elsewhere" (quoted in Dr. Swete's Introd. to Greek O. T. p.259).
The assertion has gone the round of the commentators that the Song proper is a mere expansion of Psalm cxlviii., leaving us to infer that it is hardly a work of independent authorship. Perowne  writes, "the earliest imitation of this psalm is the Song of the Three Children." And J. H. Blunt, in loc., tells us that "the hymn in its original shape was obviously an expanded form of the 148th Psalm." So even Gaster, "modelled evidently on Ps. cxlviii."  ; while Wheatley  goes so far as to say that it is "an exact paraphrase" of that psalm, "and so like it in words and sense that whoever despiseth this reproacheth that part of the canonical writings."  But though the general idea for calling upon nature to glorify God is the same, the author of Benedicite is much more than a mere expander or imitator. Naturally many of the same objects are mentioned; but while comparison with the LXX version of the psalm shews some resemblance in word and thought, it shews much more variation in style, phraseology, and treatment. That the writer, as a Jew, was acquainted with this psalm can scarcely be doubted; that he consciously imitated it there is little to shew. Moreover, the use of this psalm at Lauds in the Ambrosian, the Eastern, and Quignon's service-books; together with the Benedicite, would hardly have occurred if the Church had regarded the latter as a mere expansion of the former, and not as a distinct production.
Whoever the author may have been, he was evidently strictly orthodox, and quite in sympathy with his three heroes, in whose mouths he placed this lively, agreeable, and most religious Song. He has added a much appreciated treasure, at least among Christians, to the ecclesiastical books; a most serviceable form of utterance for the Church's praiseful voice. But the nature of the piece does not afford much scope for display of the character or personality of the writer. He effaces himself while extolling devotion to Jehovah, and, if he be Daniel, while recording the faithfulness of the blessed friends of his youth. What subject more likely to excite his enthusiastic sympathy? Honour to the martyrs who endured, praise to the Lord who delivered, it was plainly a pleasure to him to give.
 This may refer to the titles he gives from "the Vatican LXX"; but see above, p. 18, as to the absence of these.  Psalms, Lond. 1871, II. 462.  Proc. Soc. Bibl. Archaeol. 1895, p. 81.  Rational illustrat. of P. B.  But J. T. Marshall (Hastings' D. B. IV. 755), "The hymn is modelled after Ps. 136, and has equal claim to be considered poetical."
 Psalms, Lond. 1871, II. 462.
 Proc. Soc. Bibl. Archaeol. 1895, p. 81.
 Rational illustrat. of P. B.
 But J. T. Marshall (Hastings' D. B. IV. 755), "The hymn is modelled after Ps. 136, and has equal claim to be considered poetical."