Daniel 3:20-23

The fact that they were fully clothed when thrown into the furnace (Daniel 3:21) will feature later in the story. The Medo-Persian nobles later tried to have Daniel executed by getting King Darius to throw him to the lions (Daniel 6:7; cf. Revelation 12:10). That the men who threw them into the fire perished is testimony to the faithfulness of God’s promise to Abraham (Genesis 12:3). God cursed those who cursed His chosen people. Compare the fate of Haman (Esther 7:10). Their fate should have warned the king.

"Judging from bas-reliefs, it would seem that Mesopotamian smelting furnaces tended to be like an old-fashioned glass milk-bottle in shape, with a large opening for the insertion of the ore to be smelted and a smaller aperture at ground level for the admission of wood and charcoal to furnish the heat. There must have been two or more smaller holes at this same level to permit the insertion of pipes connected with large bellows, when it was desired to raise the temperature beyond what the flue or chimney would produce. Undoubtedly the furnace itself was fashioned of very thick adobe, resistant to intense heat. The large upper door was probably raised above the level of the fire bed so that the metal smelted from the ore would spill on the ground in case the crucibles were upset." [Note: Archer, "Daniel," p. 56.]