Pseudo-Jerome — as excerpted in the Catena Aurea on Mark 9:14-29

“Or else, the folly which is connected with the softness of the flesh, is healed by fasting; anger and laziness are healed by prayer. Each wound has its own medicine, which must be applied to it; that which is used for the heel will not cure the eye; by fasting, the passions of the body, by prayer, the plagues of the soul, are healed.”