| Geneva Study Bible {4} Howbeit this kind goeth not out but by {h} prayer and fasting. (4) The remedy against distrust. (h) To help us to understand the watchfulness and diligence of earnest prayer, which cannot be without sobriety. People's New Testament 17:21 This kind goeth not out but by prayer and fasting. Compare Mr 9:29. Only by devout waiting before the Lord for strength. Such strength is always needful to the victories of faith. Often, too, we have demons, envy, pride, covetousness, a revengeful spirit, that must be cast out by prayer. Wesley's Notes 17:21 This kind of devils - goeth not out but by prayer and fasting - What a testimony is here of the efficacy of fasting, when added to fervent prayer! Some kinds of devils the apostles had cast out before this, without fasting. Scofield Reference Notes Margin Howbeit The two best MSS. omit verse 21. Matthew Henry's Concise Commentary 17:14-21 The case of afflicted children should be presented to God by faithful and fervent prayer. Christ cured the child. Though the people were perverse, and Christ was provoked, yet care was taken of the child. When all other helps and succours fail, we are welcome to Christ, may trust in him, and in his power and goodness. See here an emblem of Christ's undertaking as our Redeemer. It encourages parents to bring children to Christ, whose souls are under Satan's power; he is able to heal them, and as willing as he is able. Not only bring them to Christ by prayer, but bring them to the word of Christ; to means by which Satan's strong-holds in the soul are beaten down. It is good for us to distrust ourselves and our own strength; but it is displeasing to Christ when we distrust any power derived from him, or granted by him. There was also something in the malady which rendered the cure difficult. The extraordinary power of Satan must not discourage our faith, but quicken us to more earnestness in praying to God for the increase of it. Do we wonder to see Satan's bodily possession of this young man from a child, when we see his spiritual possession of every son of Adam from the fall! | 
