Matthew Poole's English Annotations on the Holy Bible - Matthew 17:19-21
Mark repeats only what we have here Matthew 17:19,Matthew 17:21. The reason assigned here by our Saviour why his disciples could not cast out this devil, was their unbelief; not their total want, but the weakness of their faith. Christ here again lets us see the power of faith, and the mischief of unbelief. I take the plain sense of the text to be this, That there is nothing which may tend to the glory of God, or to our good, but may be obtained of God by a firm exercise of faith in him.... read more
Arthur Peake's Commentary on the Bible - Matthew 17:14-21
Matthew 17:14-Ecclesiastes : . Healing of the Demoniac Boy ( Mark 9:14-Joel : *, Luke 9:37-John :).— The story is much shorter than in Mk. The reference to possession does not come till the end; in Matthew 17:15 the child is described as epileptic. Perhaps the story was told in Q. The father’ s appeal, “ Lord, have mercy” ( Matthew 17:15), gives us the well-known “ Kyrie eleison.” Instead of prayer (the verse ( Matthew 17:21) in Mt. is spurious) and fasting ( Mark 9:29), Jesus here puts the... read more