The Prayer of Azariah and the Song of the Three Holy Children, omitted from Protestant Bibles as an apocryphal addition, is a lengthy passage following Daniel 3. This addition contains the prayer of Azariah while the three youths were in the fiery furnace, a brief account of the angel who met them in the furnace, and the hymn of praise they sang when they realized they were delivered.

These sections are retained in the Septuagint and in the Eastern Orthodox Church and Catholic canon; the "Song of the Three Holy Youths" is part of the Matins service in Orthodoxy and can be found in the Church of England Book of Common Prayer as the canticle Benedicite omnia Opera.