John Chrysostom

"And when they were come to the multitude, there came to Him a man, kneeling down to Him, and saying, Lord, have mercy on my son, for he is lunatic, and sore vexed; for ofttimes he falleth into the fire, and oft into the water. And I brought him unto Thy disciples, and they could not cure him." This man the Scripture signifies to be exceedingly weak in faith; and this is many ways evident; from Christ's saying, "All things are possible to him that believeth;" from the saying of the man himself that approached, "Help Thou mine …

Homily on the Gospel of Matthew 57 ↗

Theophylact of Ohrid

And when they were come to the multitude, there came to Him a certain man, kneeling down to Him, and saying, Lord, have mercy on my son: for he is lunatic, and sore vexed: for ofttimes he falleth into the fire, and oft into the water. That this man is exceedingly faithless is clear from the words which Christ spoke in reply to him, "O faithless generation," and from the fact that the man himself blamed the disciples. …

Commentary on Matthew ↗

Jerome

Lord, have mercy on my son, for he is a lunatic and suffers greatly: for he often falls into fire and frequently into water. And I brought him to your disciples, but they could not heal him. This is why the devil, observing the course of the moon, seizes upon men and strives to defame the Creator through His creatures, as we have said above. …

Commentary on Matthew ↗

Thomas Aquinas

And when he had come: here he foretells the tranquility of glory, which is assailed by the oppression of demons and the disturbance of men. And first he foretells the cessation of the first through the healing of the lunatic; secondly, the second. And concerning the first, first the healing of the lunatic is presented; secondly, he foretells the passion, at and when they conversed together in Galilee, etc.; thirdly, concerning the payment of the tribute, at and when they had come to Capharnaum, etc. …

Commentary on Matthew ↗