Mark 9:17-18

17One of the men in the crowd spoke up and said, “Teacher, I brought my son so you could heal him. He is possessed by an evil spirit that won’t let him talk.

18And whenever this spirit seizes him, it throws him violently to the ground. Then he foams at the mouth and grinds his teeth and becomes rigid. So I asked your disciples to cast out the evil spirit, but they couldn’t do it.”