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17One of the multitude answered, "Teacher, I brought to you my son, who has a mute spirit; 18and wherever it seizes him, it dashes him down, and he foams at the mouth, and grinds his teeth, and wastes away. I asked your disciples to cast it out, and they weren`t able." 19He answered them, "Unbelieving generation, how long will I be with you? How long will I bear with you? Bring him to me." 20They brought him to him, and when he saw him, immediately the spirit convulsed him, and he fell on the ground, wallowing and foaming at the mouth.
Mark 9:17-20 (WEB)