Matthew
King James Version (KJV)

“Howbeit this kind goeth not out but by prayer and fasting.”
King James Version (KJV)
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.
Mt 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.