Mark 9:17-18 ▼

17 And one person from the crowd answered Him, “Teacher, I brought You my son, because he has a spirit that makes him unable to speak;

18 and whenever it seizes him, it slams him to the ground, and he foams at the mouth and grinds his teeth and becomes stiff. And I told Your disciples so that they would cast it out, but they could not do it.”