When Jesus came down from the mountain, great crowds followed him. And then a leper approached, did him homage, and said, "Lord, if you wish, you can make me clean." He stretched out his hand, touched him, and said, "I will do it. Be made clean." His leprosy was cleansed immediately. Then Jesus said to him, "See that you tell no one, but go show yourself to the priest, and offer the gift that Moses prescribed; that will be proof for them." (Mt 8:1-4)
Leprosy was not only a physical ailment but also it had its social segregation. They were forced to move out of the society and the society moved away from them. Nobody approached them. Here Jesus reached out to him and touched him. We could imagine the repugnant feeling that was going through the onlookers. On the other hand there was life and warmth and newness going through the leper himself.
More than the physical healing (of course he needed that), the leper needed reintegration into the society. He needed to get back into his family, into his village. For this he needed authorization and that is why Jesus asked him to show himself to the priest and offer the gift that Moses prescribed. The leper needed to be restored as a member of Israel.
This is a miracle. Not a magic. It is a miracle because it restored the individual and made him get back into the believing community. And he himself expressed his faith. Miracle takes place when there is faith, believing community, restoration. In short, miracle takes place where there is God and people of God.