New Defender's Study Bible Notes
9:34 prince of the devils. The “prince of the demons,” of course, is Satan. Satan has always attempted to control the actions of as many men and women as possible as part of his anti-God strategy, and the most effective way to do this is through actual demonic possession. It would be completely unreasonable for Satan to renounce this control (compare Matthew 12:26), once he has obtained it.