If integrated into the book of Daniel: 3.24
They: In the context of Dan 3, it is clear to whom they refers. According to Dan 3.22-23, they refers to Shadrach, Meshach, and Abednego. If translators include “The Prayer of Azariah and the Song of the Three Young Men” as part of Dan 3, they needs no further clarification. But if they translate it as a separate book of the Apocrypha, it would be helpful to identify the three young men referred by this pronoun. If this is done, the forms used in Good News Translation, “Hananiah, Mishael, and Azariah,” are appropriate. These are the original names of the three men (see Dan 1.6-7).
Walked about in the midst of the flames: Good News Translation interprets the Greek verb form rendered walked about as placing emphasis on the beginning of the action: “started walking around.” In English this makes for a smoother beginning to the narrative, whether as a separate story or as part of Dan 3. In the midst of the flames may be also expressed as “in the flames [or, fire]” (so Good News Translation, Contemporary English Version).
Singing hymns to God and blessing the Lord: Any translation must of course make certain that readers will not interpret God and the Lord as two different beings. Good News Translation guards against this with a subtle rephrasing: “singing hymns to God, and praising him as the Lord.” Other options would be to choose just one of the two words, or to use them both together; for example, “the Lord God” (as in verse 3). For a comment on the translation of Lord, see Bar 1.5. Blessing here refers to praise, as Good News Translation and Contemporary English Version have taken it. Here it is used as a verb; it will reappear as an adjective as the first word of the prayer itself (see the comments on verse 3). Presumably it is in the singing of hymns that the three are praising God, and this could be made clear by saying “praising God by singing hymns” or “singing hymns of praise to God.”
Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on The Shorter Books of the Deuterocanon. (UBS Helps for Translators). New York: UBS, 2006. For this and other handbooks for translators see here.