Commentaries
20:30. Severe rebukes sometimes do a great deal of good. But such is the corruption of nature, that men are loth to be rebuked for their sins. If God uses severe afflictions, to purify our hearts and fit us for his service, we have cause to be very thankful.
30. blueness—literally, "joining," the process of uniting the edges of a wound throws off purulent matter.
stripes … belly—So punishment provides healing of soul (Pr 18:8), by deterring from evil courses.