31 Ananias, Azarias, and Misael, the illustrious and noble youths, even amid the flames and the ardours of a raging furnace, did not desist from making public confession to God. Although possessed of a good conscience, and having often deserved well of the Lord by obedience of faith and fear, yet they did not cease from maintaining their humility, and from making atonement to the Lord, even amid the glorious martyrdoms of their virtues. The sacred Scripture speaks, saying, “Azarias stood up and prayed, and, opening his mouth, made confession before God together with his companions in the midst of the fire.” Daniel also, after the manifold grace of his faith and innocency, after the condescension of the Lord often repeated in respect of his virtues and praises, strives by fastings still further to deserve well of God, wraps himself in sackcloth and ashes, sorrowfully making confession, and saying, “O Lord God, great, and strong, and dreadful, keeping Your covenant and mercy for them that love You and keep Your commandments, we have sinned, we have committed iniquity, and have done wickedly: we have transgressed, and departed from Your precepts, and from Your judgments; neither have we hearkened to the words of Your servants the prophets, which they spoke in Your name to our kings, and to all the nations, and to all the earth. O Lord, righteousness belongs unto You, but unto us confusion.”
Source: The Treatises of Cyprian (New Advent)