You must burn them to make a smoke: Good News Translation misses an important element in the smoke. It is not a charred part of the fish that can be “used to chase away a demon,” but the smoke produced by the fire burning the fish’s heart and liver. The Contemporary English Version rendering gives us this information very clearly: “take the heart and liver and burn them nearby. The smoke will stop….”
In the presence of a man or woman afflicted by a demon or evil spirit: In some cases in the Old Testament, the term demon refers to an “idol” that represents an evil spirit, but in this present passage the terms seem to mean the same thing. Most cultures have words for these “evil” or “dirty” spirits that are thought to cause harm to human beings (see also 3.8).
Every affliction will flee away and never remain with that person any longer: Affliction (Good News Translation “attacks”) translates the same Greek word as afflicted (Good News Translation “tormenting”) used earlier in the verse. This word is used at Eccl 9.11, “time and chance happen to them all,” but the word may have an active component of “attack” or “aggression.” That appears to be its significance here. Good News Translation “attacks” may be too narrow in meaning since it suggests affliction with an epileptic attack of some kind. In many languages it will seem strange to talk about every affliction “running away.” In such cases it will be helpful to show that the demon is the agent of the afflictions and torments, and say something like “the demon will run away and will never bother the person again.”
An alternative translation model for this verse is:
• The angel said, “If a demon [or, evil/dirty spirit] is tormenting a man or woman, take the fish’s heart and liver and burn them to make smoke near the person. This will cause the demon to run away and never torment [or, bother] the person again.”
Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Tobit. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here.