Mark 9:15-19

And straightway all the people, when they beheld him, were greatly amazed, and running to him saluted him.

And he asked the scribes, What question ye with them?

And one of the multitude answered and said, Master, I have brought unto thee my son, which hath a dumb spirit;

And wheresoever he taketh him, he teareth him: and he foameth, and gnasheth with his teeth, and pineth away: and I spake to thy disciples that they should cast him out; and they could not.

He answereth him, and saith, O faithless generation, how long shall I be with you? how long shall I suffer you? bring him unto me.