Mark 9:16-18

9:16 He asked them, “What are you arguing about with them?” 9:17 A member of the crowd said to him, “Teacher, I brought you my son, who is possessed by a spirit that makes him mute. 9:18 Whenever it seizes him, it throws him down, and he foams at the mouth, grinds his teeth, and becomes rigid. I asked your disciples to cast it out, but they were not able to do so.”