From: Mark 5:1-20
The Gerasene Demoniac
 They came to the other side of the sea, to the country of the Gerasenes.  And when He (Jesus) had come out of the boat, there met Him out of the tombs a man with an unclean spirit,  who lived among the tombs; and no one could bind him any more, even with a chain;  for he had often been bound with fetters and chains, but the chains he wrenched apart, and the fetters he broke in pieces; and no one had the strength to subdue him.  Night and day among the tombs and on the mountains he was always crying out, and bruising himself with stones.  And when he saw Jesus from afar, he ran and worshipped Him;  and crying out with a loud voice, he said, "What have You to do with me, Jesus, Son of the Most High God? I adjure You by God, do not torment me."  For He had said to him, "Come out of the man, you unclean spirit!"  And Jesus asked him, "What is your name?" He replied, "My name is Legion; for we are many."  And he begged Him eagerly not to send them out of the country.  Now a great herd of swine is feeding there on the hillside;  and they begged Him, "Send us to the swine, let us enter them."  So, He gave them leave. And the unclean spirits came out, and entered the swine; and the herd, numbering about two thousand, rushed down the steep bank into the sea, and were drowned in the sea.
 The herdsmen fled, and told it in the city and the country. And people came to see what it was that had happened.  And they came to see Jesus, and saw the demoniac sitting there, clothed and in his right mind, the man who had had the legion; and they were afraid.  And those who had seen it told what had happened to the demoniac and to the swine.  And they began to beg Jesus to depart from their neighborhood.  And as He was getting into the boat, the man who had been possessed with demons begged Him that he might be with Him.  But He refused, and said to him, "Go home to your friends, and tell them how much the Lord has done for you, and how He has had mercy on you."  And he went away and began to proclaim in the Decapolis how much Jesus had done for him; and all men marvelled.
1-20. The inhabitants of Gerasa were mostly pagans, as one can gather from the fact that there was such a huge herd of swine there (which must have belonged to a number of different people). Jews were forbidden to raise pigs or eat pork (Leviticus 11:7).
This miracle emphasizes, once more, the existence of the devil and his influence over men's lives: if God permits it, the devil can harm not only humans but also animals. When Christ allows the demons to enter the swine, the malice of the demons becomes obvious: they are tormented at not being able to do men harm and therefore they ask Christ to let them, at least, inflict themselves on animals. This He does, in order to show that they would have the same effect on men as they have on these swine, if God did not prevent them.
Clearly it was not Jesus' intention to punish the owners of the swine by the loss of the herd: since they were pagans that were not subject to the precepts of the Jewish law. Rather, the death of the swine is visible proof that the demon has gone out of the possessed man.
Jesus permitted the loss of some material goods because these were of infinitely less value than the spiritual good involved in the cure of the possessed man.
15-20. Notice the different attitudes to Jesus Christ: the Gerasenes beg Him to go away; the man freed from the devil wants to stay with Him and follow Him. The inhabitants of Gerasa have had our Lord near them, they have seen His divine powers, but they are very self-centered: all they can think about is the material damage they have suffered through the loss of the herd; they do not realize the marvel Jesus has worked.
Christ has invited them and offered them His grace but they do not respond: they reject Him. The man who has been cured wants to follow Jesus with the rest of His disciples but our Lord refuses; instead He gives him a task which shows Christ's unlimited compassion for all men, even for those who reject Him: the man is to stay in Gerasa and proclaim to the whole neighborhood what the Lord has done for him.
Perhaps they will think again and realize who He is who has visited them, and escape from the sins their greed has led them to commit. These two attitudes are to be found whenever Christ passes by--as are Jesus' mercy and continuous offer of grace: our Lord does not want the death of the sinner but rather that he should turn from his way and live. (cf. Ezekiel 18:23).
20. The "Decapolis" or "country of the ten cities", among the more famous of which are Damascus, Philadelphia, Scythopolis, Gadara, Pella and Gerasa. The region was located to the east of the lake of Gennesaret and was inhabited mainly by pagans of Greek and Syrian origin. This territory came under the Roman governor of Syria.
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.