And they brought him unto him: and when he saw him, straightway the spirit tare him; and he fell on the ground, and wallowed foaming. When he saw him the spirit tare him; and he fell on the ground, etc. - When this demon saw Jesus, he had great rage, knowing that his time was short; and hence the extraordinary convulsions mentioned above.
Related Commentaries of Mark 9:20
Mark 9:20
20 And they brought him unto him: and when he saw him, straightway the spirit tare him; and he fell on the ground, and wallowed foaming.