Mark 9:27 ASV

²⁵  And when Jesus saw that a multitude came running together, he rebuked the unclean spirit, saying unto him, Thou dumb and deaf spirit, I command thee, come out of him, and enter no more into him.

²⁶  And having cried out, and torn him much, he came out: and 'the boy' became as one dead; insomuch that the more part said, He is dead.

²⁷  But Jesus took him by the hand, and raised him up; and he arose.

²⁸  And when he was come into the house, his disciples asked him privately, 'How is it' that we could not cast it out?

²⁹  And he said unto them, This kind can come out by nothing, save by prayer.