The spirit cried out because Jesus was already commanding it to leave: "For he said unto him, Come out of the man, thou unclean spirit" (Mark 5:8). The question tries to push Jesus away. Barnes explains the expression as meaning "Why dost thou trouble or disturb us?" The spirit knew exactly who Jesus was, "Son of the most high God," but it wanted nothing to do with Him. Gill puts it this way: "they had nothing to do with him as a Saviour, though he had something to do with them as a judge." The plea that follows, "torment me not," shows fear. Gill notes that "it is torment to a devil to be cast out of a man, or to have his power curtailed."

Jesus did not argue. He answered with a question of His own: "What is thy name?" and the reply came, "My name is Legion: for we are many" (Mark 5:9). The spirits begged not to be sent "out of the country" and asked to enter a herd of swine, and "forthwith Jesus gave them leave" (Mark 5:10-13). About two thousand swine ran down a steep place into the sea. The townspeople then found the man "sitting, and clothed, and in his right mind" (Mark 5:15). The spirit had asked what it had to do with Jesus; the answer was that it had to go.

The Greek behind "What have I to do with thee" is very short: ti emoi kai soi, literally "what to me and to you?" Barnes notes that Matthew's form could just as well be translated "What hast thou to do with us?" The title "most high God" uses hypsistos, the Most High. The word for "torment" (basanizo) means, in Thayer's definition, "to vex with grievous pains (of body or mind), to torment."

The man lived "in the tombs" (Mark 5:3, 5). Barnes explains that Jewish graves were often caves outside the cities, which "afforded, therefore, to insane persons and demoniacs a place of retreat and shelter." Matthew's account adds the words "before the time" (Matthew 8:29), which Barnes takes as the day of judgment.

This question shows that the powers of darkness know who Jesus is. Unclean spirits in Mark repeatedly name Him: "the Holy One of God" (Mark 1:24) and "the Son of God" (Mark 3:11). Gill observes that "Devils believe there is one God, and tremble at him; and they confess that Jesus of Nazareth" is the Son of God. Knowing the right title, though, did not bring them any closer to Him.

The chapter answers the question in a surprising way. The spirit asked, in effect, "What do You have to do with me?" Jesus had everything to do with the man the spirit was holding. By the end, the man who once ran among the tombs begged Jesus "that he might be with him," and Jesus sent him home to tell "how great things the Lord hath done for thee, and hath had compassion on thee" (Mark 5:18-19).