The Account in Daniel
According to the Book of Daniel, King Nebuchadnezzar set up a golden image on the plain of Dura and ordered that all his officials bow before it, on pain of being thrown into a furnace. When it was reported that the three youths refused to worship the image, they were brought before the king and declared that they would not comply, trusting that their God would deliver them.
The furnace was heated, by the narrative, seven times hotter than usual, and the three were cast in; yet they were seen walking unharmed amid the flames, accompanied by a fourth figure described as "like a son of God." They emerged untouched, with not a hair singed nor any smell of fire upon them. Their deliverance is traditionally paired with the account of Daniel in the lions' den as a witness that God preserves the faithful. In Orthodox tradition the figure who appeared in the furnace is understood to be Christ, and icons of the scene depict him with a cross-bearing halo.