John Chrysostom

(ubi sup.) The Scriptures declare that this man was weak in faith, for Christ says, O faithless generation: and He adds, If thou canst believe. But although his want of faith was the cause of their not casting out the devil, he nevertheless accuses the disciples; wherefore it is added, And I spake to thy disciples that they should cast him out; but they could not. Now observe his folly; in praying to Jesus in the midst of the crowd, he accuses the disciples, wherefore the Lord before the multitude so much the more accuses him, and not only aims the accusation at himself, but also extends it to all the Jews; for it is probable that many of those present had been offended, and had held wrong thoughts concerning His disciples. Wherefore there follows, He answereth them and saith, O faithless generation, how long shall I be with you? how long shall I suffer you? By which He shewed both that He desired death, and that it was a burden to Him to converse with them.