The exorcism account in the book of Tobit is an important story for us to study as it gives us an understanding of second temple period Judaism and early Christian views on the topic of demon possession and exorcism.

Background of Tobit
Tobit was from Israel and part of the deportation to Assyria. This story should give some insight in how Jews saw demon possession. This would be either from the time of the exile, although others would give the book a later date sometime during second temple period.

Situation
A girl named Sarah was possessed by a demon named Asmodeus and that demon caused the death of 7 of her husbands. I have to wonder how the 3, 4, 5, 6 and 7 husbands felt about their respective engagements. I would be leery if I was husband 2 let alone 7. Sarah's solution to this problem was suicide; however, she did not go through with it. Instead she prayed to God to take her life, rather than bring dishonor to her father by committing suicide. Her concern about suicide was not the disposition of her soul; she wanted to protect her families honor over relief from her possession.

One noteworthy part of this story is the desire for the possessed person to seek death. Sarah sought suicide but ultimately did not. Contemporary cases of supposed demon possession often include suicidal tendencies. Her we have a correlate between ancient evens and contemporary events leading us to the conclusion that one indication of possession is the desire to relief themselves by committing suicide.

In answer to Sarah's prayer, Raphael (one of the 7 archangels) was dispatched and Sarah was given Tobit's son Tobis for marriage. God answered her prayer to take her life with an alternative she did not ask for. I wonder why she did not ask for a solution other than death. In any case God answer the prayer with angelic assistance.

Events were arranged to bring Tobis to Sarah. Raphael disguised as a distant relative agrees to accompany Tobis for protection on a trip for him to recover money for his father. Raphael accompanied Tobis on that trip, and during their travels they stop along the way and Raphael tells him to catch a fish and gut it.

“Cut open the fish and take out its gall, heart, and liver. Keep them with you, but throw away the intestines. For its gall, heart, and liver are useful as medicine.” Tobit 6:5 NRSV

Raphael later explains why he wanted Tobis to keep the fish guts.

“As for the fish’s heart and liver, you must burn them to make a smoke in the presence of a man or woman afflicted by a demon or evil spirit, and every affliction will flee away and never remain with that person any longer. And as for the gall, anoint a person’s eyes where white films have appeared on them; blow upon them, upon the white films, and the eyes will be healed.” Tobit 6:8–9 NRSV

Raphael arranges for Tobis to meet Sarah and take her as wife. Raphael gives Tobis instructions on how to expel the demon.

"When you enter the bridal chamber, take some of the fish’s liver and heart, and put them on the embers of the incense. An odor will be given off; the demon will smell it and flee, and will never be seen near her any more. Now when you are about to go to bed with her, both of you must first stand up and pray, imploring the Lord of heaven that mercy and safety may be granted to you. Do not be afraid, for she was set apart for you before the world was made. You will save her, and she will go with you." Tobit 6:17–18 NRSV

This is an interesting text. Apparently, according to this text, demons, which are spiritual entities, have senses here in the physical world. Did they use the senses of Sarah or did they have their own? Does the fish liver and heart have some sort of energy or power? Some exorcists claim that objects can by bless, that is imbued with some sort of spiritual power, most notably Catholics. Other exorcists, however, do not feel that objects such as holy water or crosses have any power or do anything to remove demons. They feel the power that removes the demon is the name of Jesus Christ or the faith of the exorcist in conjunction with the faith of the possessed. In this story the burning of the fish liver and heart acts as an irritant and there is no indication that there is some sort of spiritual power related to burning the dead fish parts. I guess dead fish smell is so bad it can scare demons away ;-).

Another interesting point here is that Raphael promises the demon will not return. However we will see later that Jesus indicates demons can return and even stronger (Luke 11:24-26). Raphael also tells them to pray for safety. Today paranormal investigators and sensitives will often prey for protection if they think they are going into a hostile area. Again we see a correlation between modern activities and ancient ones.

Tobis follows Raphael's instructions.

"Then Tobias remembered the words of Raphael, and he took the fish’s liver and heart out of the bag where he had them and put them on the embers of the incense. The odor of the fish so repelled the demon that he fled to the remotest parts of Egypt. But Raphael followed him, and at once bound him there hand and foot." Tobit 8:2–3 NRSV

I have to admit the resolution is not what I expected. The demons fled to Egypt and Raphael bound him there. What does that mean? Why did the demon go to Egypt? Is this how Raphael knows that the demon would not return because he was going to bind him?

Footnote
Tobit is an apocryphal book used by most Christian groups Catholic, Eastern Orthodox, Ethiopian Orthodox and some Protestants. It is also included in LXX, [Septuagint], Vulgate and five fragments were found at Qumran.
The cannon was created to include books that were thought to be inspired by God. This does not mean books outside of cannon are not true, it simply means some people don't think it is inspired by God. I include this as an example of Jewish exorcism.
http://en.wikipedia.org/wiki/Biblical_canon