11 Where now are those who said, “Let the Emperor take all, and grant us our bodies free?” Let such go and learn what is a free body. It is not immunity from punishment that makes the body free, but perseverance in a life of righteousness. The bodies of these youths, for instance, were free, though they were given over to the furnace, because they had before put off the slavery of sin. For this alone is liberty; and not an immunity from punishment, or from suffering anything fearful.
But having heard of the furnace, call thou to mind the “rivers of fire,” which there shall be in that fearful day. For as on the above occasion, the fire seized upon some, but reverenced others, so also shall it be with those rivers. If any one should then have hay, wood, stubble, he increases the fire; but if he has gold and silver, he becomes the brighter. Let us therefore get together this kind of material, and let us bear the present state of things nobly; knowing that this tribulation will both bring us deliverance from that punishment if we understand how to practise true wisdom, and will also make us better here; and not only us, but often those too, who throw us into trouble, if we be vigilant; so abundant is the force of this spiritual wisdom; which was the case then even with the tyrant.
For when he knew that they had suffered no harm, hear how he changed his language. “You servants of the most high God, come forth, and come hither.” Did not you say, a little before “Who is that God that shall deliver you out of my hands?” What has happened? Whence this change? Thou saw those without destroyed, and do you call on those within? Whence has it come to pass that you are grown wise in such matters. You see how great a change took place in the monarch! Whilst he had not yet exercised his power over them, he blasphemed, but as soon as he had cast them into fire, he began to show moral wisdom.
For this reason also God permitted all to take place, whatsoever the tyrant wished, in order that He might make it manifest, that none will be able to injure those who are kept by Him. And what He did towards Job, He performed here. For on that occasion also, He permitted the devil to manifest all his power; and not till he had exhausted all his darts, and no further mode of plotting against him remained, was the combatant led out of the field, that the victory might be brilliant and indubitable.
So here too He did the very same thing. He willed to overthrow their city, and God stayed him not: he willed to carry them away captive, and He hindered him not: he willed to bind them, and He permitted; to cast them into the furnace, and He allowed it: to heat the flame beyond its measure, and this too He suffered; and when there was nothing further left for the tyrant to do, and he had exhausted all his strength, then God manifested His own power, and the patience of the youths.
Do you see how God permitted these tribulations even to the end, that He might show the assailants the spiritual wisdom of those whom they assailed, as well as His own providence. Both of which circumstances also that man then discerned, and cried out, “You servants of the most high God, come forth, and come hither.”
Source: Homilies on the Statues (New Advent)