Mark 9:18

“And wheresoever he taketh him, etc..] The spirit, or devil, whether it be near fire, or water, whatsoever danger, or dangerous place: he teareth him; or throws him into it, or dashes him against it; or inwardly racks, tortures, and convulses him: and he foameth; at the mouth, like one that is mad: and gnasheth with his teeth; through the excessive pain he is in: and pineth away; his flesh is withered, dried up, and consumed away. This was the sad deplorable case this child was in, who was his father's only child, and therefore his health and life were very desirable: now he further observes to Christ, saying, and I spake to thy disciples that they should cast him out, and they could not.…”

“See this passage explained in the notes at Matthew 17:14-21. Mark 9:14 Questioning with them - Debating with the disciples, and attempting to confound them. This he saw as he came down from the mount. In his absence they had taken occasion to attempt to perplex and confound his followers. Mark 9:15 Were greatly amazed - Were astonished and surprised at his sudden appearance among them. Saluted him - Received him with the customary marks of affection and respect. It is probable that this was not by any “formal” manner of salutation, but by the “rush” of the multitude, and by hailing him as the Messiah. Mark 9:16 What question ye? - What is the subject of your inquiry or debate with the…”

“9:18 These symptoms are often associated with epilepsy (see Matt 17:15), but Mark emphasizes the demonic origin of the child’s problem (Mark 9:17-18, 25-26, 28). The disciples’ inability to heal the child magnifies the effect of Jesus’ power (9:25-26).”

“teareth him: or, dasheth him, Mar 9:26; Mat 15:22; Luk 9:39 he foameth: As these symptoms accord very much with those of epileptic persons, some have ventured to assert that it was no real possession; but the evangelist expressly affirms that he had a "dumb spirit" which tare him, that our Lord charged him to "come out of him," etc. Mar 9:20; Jde 1:13 gnasheth: Job 16:9; Psa 112:10; Mat 8:12; Act 7:54 and they: Mar 9:28, Mar 9:29, Mar 11:23; Kg2 4:29-31; Mat 17:16, Mat 17:19-21; Luk 9:40 Mark 9:19”