Matthew Henry Commentary Proverbs 20:30

"Stripes that wound cleanse away evil; And strokes [reach] the innermost parts." — Proverbs 20:30 (ASV)

Severe rebukes sometimes do a great deal of good. But such is the corruption of nature, that people are unwilling to be rebuked for their sins. If God uses severe afflictions, to purify our hearts and prepare us for his service, we have cause to be very thankful.