‘And Jesus rebuked him saying, “Be quiet and come out of him.” And the unclean spirit, tearing him and crying with a loud voice, came out of him.'
Jesus rejected the testimony of the evil spirit. He did not want testimony from such sources, although He would later point to His power over evil spirits as evidence that He was from God and that God's Kingly Rule had come (Mark 3:21-30; compare Matthew 12:28). But that was only because of necessity at the accusations levelled against Him. The word for ‘be quiet' means literally, ‘Be muzzled.' He then commanded the spirit to come out, and the immediate result was that, convulsing the man, and crying with a loud voice, it came out.
‘Jesus rebuked it.' The word for rebuke is the equivalent of that used for the divine rebuke in the Old Testament, a rebuke which was powerfully effective (2 Samuel 22:16; Job 26:11; Psalms 80:16; Psalms 104:7; Psalms 106:9). It is especially used when YHWH rebukes Satan in Zechariah 3:2, after which no more is heard from him. Thus we are to see in this rebuke the power of the Lord. It carried divine authority. In this case it was addressed to the evil spirit.
‘Be quiet.' Jesus never accepts the testimony of evil spirits. This is not on a parallel with His attempt to prevent people spreading the idea that He was the Messiah. He did that when on Jewish territory because the Jews had the wrong idea about Messiahship, seeking a military leader against the Romans (see John 6:15). But He was quite happy to tell a Samaritan woman in Samaria that He was the Messiah (John 4:25-26), and content that she should inform her fellow Samaritans. And He would later tell a man in Gentile Decapolis to go and tell what the Lord had done for Him and how He had had compassion on him (Mark 5:19). But He wanted no testimony from evil spirits which might give men the wrong ideas about Him. He did not want to be seen as associated with them in any way.
‘And come out of him.' The command was clear. It must relinquish its hold on the man.
‘And the unclean spirit, tearing him and crying with a loud voice, came out of him.' To the awe of the watchers there was a terrible cry and the man was clearly visibly distressed and convulsed, and then the spirit was gone. The man was in his right mind. This is a regular description of release from genuine spirit possession.