John Wesley on Acts 9:3

And suddenly - When God suddenly and vehemently attacks a sinner, it is the highest act of mercy. So Saul, when his rage was come to the height, is taught not to breathe slaughter. And what was wanting in time to confirm him in his discipleship, is compensated by the inexpressible terror he sustained. By his also the suddenly constituted apostle was guarded against the grand snare into which novices are apt to fall.