Matthew 17:19-21

19Then the disciples came to Jesus in private and asked, “Why couldn’t we drive it out?” 20He replied, “Because you have so little faith. Truly I tell you, if you have faith as small as a mustard seed, you can say to this mountain, ‘Move from here to there,’ and it will move. Nothing will be impossible for you.”

21Some manuscripts include here words similar to Mark 9:29.