Proverbs 20:30 New English Translation

³⁰Beatings and wounds cleanse away^[a] evil,
and floggings cleanse^[b] the innermost being.^[c]

Proverbs 20:30 tc The verb מָרַק (maraq) means “to polish; to scour”; in the Hiphil it means “to cleanse away,” but it is only attested here, and that in the Kethib reading of תַּמְרִיק (tamriq). The Qere has תַּמְרוּק (tamruq, “are a means of cleansing”). The LXX has “blows and contusions fall on evil men, and stripes penetrate their inner beings”; the Latin has “the bruise of a wound cleanses away evil things.” C. H. Toy suggests emending the text to read “stripes cleanse the body, and blows the inward parts” or “cosmetics purify the body, and blows the soul” (Proverbs [ICC], 397). Cf. CEV “can knock all of the evil out of you.”
Proverbs 20:30 tn The term “cleanse” does not appear in this line but is supplied in the translation in the light of the parallelism.
Proverbs 20:30 sn Physical punishment may prove spiritually valuable. Other proverbs say that some people will never learn from this kind of punishment, but in general this may be the only thing that works for some cases.

New English Translation (NET)