When Jesus saw that the crowd was gathering around, He rebuked the unclean spirit, saying to it, “Mute and deaf spirit, I command you: come out of him and never enter into him again.”
The Lord addresses the evil spirit with authority. He does not resort to any means, but commands as Lord. In the words “I command you,” His divine authority is revealed. He also forbids the spirit to return again, because His deliverance is not partial and temporary, but complete. The fact that the Lord acted before the people had fully gathered is also instructive: He does not act to stir people’s amazement, but out of mercy. His aim was not the crowd’s astonishment, but the boy’s deliverance and the strengthening of faith.