John Mark
Mark 9:21KJV·traditional attribution

And he asked his father, How long is it ago since this came unto him? And he said, Of a child.

John Calvin Reformed

21. From a child. Hence we infer that this punishment was not inflicted on account of the sins of the individual, but was a secret judgment of God. True indeed, even infants, as soon as they have come out of the womb, are not innocent in the sight of God, or free from guilt; but God’s chastisements have sometimes hidden causes, and are intended to try our obedience.

Matthew Henry Presbyterian

We have here the story of Christ casting the devil out of a child, somewhat more fully related than it was in Mat 17:14, etc. Observe here, I. Christ's return to his disciples, and the perplexity he found them in. He laid aside his robes of glory, and came to look after his family, and to enquire what was become of them.

Commenting on Mark 9:14-29

John Gill Reformed Baptist

And he asked his father,.... As he lay rolling about in this miserable condition, that the length and stubbornness of his disorder might be known, and so the cure the more remarkable, and appear the more expressive of his divine power and goodness: how long is it ago since this came unto him? since this evil spirit entered into him, and these disorders have attended him?