He is lunatic — This word might with great propriety he used, though the case was mostly preternatural; as the evil spirit would undoubtedly take advantage of the influence which the changes of the moon have on the brain and nerves.
Related Commentaries of Matthew 17:15
Matthew 17:15
15 Lord, have mercy on my son: for he is lunatick, and sore vexed: for ofttimes he falleth into the fire, and oft into the water.