So that the flame streamed forth above the furnace forty and nine cubits.
Read Chapter 3
Hippolytus of Rome
The fire, he means, was driven from within by the angel, and burst forth outwardly. See how even the fire appears intelligent, as if it recognised and punished the guilty. For it did not touch the servants of God, but it consumed the unbelieving and impious Chaldeans. Those who were within were besprinkled with a (cooling) dew by the angel, while those who thought they stood in safety outside the furnace were destroyed by the fire. The men who cast in the youths were burned by the flame, which caught them on all sides, as I suppose, when they went to bind the youths.