Better, The blueness of a wound is a cleansing of evil, so are the stripes that go down to the inward parts of the belly.
The open sores of wounds left by the scourge, unclean and foul as they seem, are yet a cleansing, purifying process for evil; so also are the stripes that reach the inward parts of the belly, i. e., the sharp reproofs, the stings of conscience, which penetrate where no scourge can reach, into the inner life of man. Chastisement, whatever be its nature, must be real; the scourge must leave its mark, the reproof must go deep.

The blueness of a wound - חברות chabburoth, from חבר chabar, to unite, to join together. Does it not refer to the cicatrice of a wound when, in its healing, the two lips are brought topether? By this union the wound is healed; and by the previous discharge the lace-rated ends of fibres and blood-vessels are purged away. So stripes, though they hurt for the time, become the means of correcting and discharging the moral evil of the inmost soul, the vice of the heart, the easily-besetting sin.
In this chapter, verses fourteen to nineteen, inclusive, are wanting in the Septuagint and Arabic; and the tenth, eleventh, twelfth, and thirteenth, come in after the twenty-second. It is difficult to account for these variations, unless they were occasioned by the change of leaves in MSS.

(k) The blueness of a wound cleanseth away evil: so [do] stripes the inward parts of the belly.
(k) Sharp punishment that pierces even the inward parts is profitable for the wicked to bring them to amendment.

The blueness of a wound cleanseth away evil,.... Rubs it off and scours it away, as the word (m) signifies, or is a clearing and rubbing it off; some men must be beaten black and blue, or must have very sore correction, before they can be reclaimed and reformed from their evil ways; so some interpret it of the evil man (n): sanctified afflictions to God's people are the means of purging away their iniquities, their dross, and their sin; but there is nothing so effectually cleanses from sin as the blood of Jesus, or heals or cures of it as his blue wounds and stripes; see Isaiah 27:9;
so do stripes the inward part of the belly; or heart and conscience; by means of corrections and chastisement men are brought to an inward sense of sin; they are shown their transgressions wherein they have exceeded, and are commanded to return from iniquity, Job 36:9; they lament and mourn over sin, confess it and forsake it; and then may the inwards of the heart, the mind and conscience, defiled with them, be said to be cleansed from them; especially when led by these stripes and corrections to the stripes, wounds, and blood of Christ which, being applied, cleanse from all, sin inwardly and outwardly.
(m) "abstesio", Piscator, Mercerus, Cocceius; "detersio", Montanus, Michaelis; "effricatio", Schultens. (n) "in malo, sub, homine", Vatablus, Mercerus, Gejerus, Michaelis; "in malo (homine nequam)", Schultens, so Aben Ezra.

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.

blueness--literally, "joining," the process of uniting the edges of a wound throws off purulent matter.
stripes . . . belly--So punishment provides healing of soul (Proverbs 18:8), by deterring from evil courses.

30 Cutting wounds cleanse away evil,
And reach the inner parts of the body.
The two words for wounds in line first stand in the st. constr.; חבּוּרה (from חבר, to be bound around with stripes, to be striped) is properly the streak, the stripe; but is here heightened by פּצע (from פּצע, to cleave, split, tear open), beyond the idea of the stripe-wound: tearing open the flesh, cuts tearing into the flesh. The pred. is after the Kerı̂ תּמרוּק; but this substantive, found in the Book of Esther, where it signifies the purification of the women for the harem (according to which, e.g., Ahron B. Joseph explains כמו תמרוק לנשׁים שׁהוא יפה להם), is syntactically hard, and scarcely original. For if we explain with Kimchi: wounds of deep incision find their cleansing (cure) by evil, i.e., by means which bring suffering (according to which, probably the Venet. μώλωπες τραύματος λάμψουσιν ἐν κακῷ), then תמרוקן, with the pronoun pointing back, one would have expected. But the interpretation of בּרע, of severe means of cure, is constrained; that which lies nearest, however, is to understand רע of evil. But if, with this understanding of the word, we translate: Vibices plagarum sunt lustratio quae adhibetur malo (Fleischer), one does not see why בּרע, and not rather gen. רע, is used. But if we read after the Chethı̂b תּמריק, then all is syntactically correct; for (1.) that the word ימריקוּ, or תּמרקנה, is not used, is in accordance with a well-known rule, Gesen. 146. 3; and (2.) that המריק is connected, not directly with an accus. obj., but with ב, has its analogy in התעה ב, Jeremiah 42:2, השׁרישׁ בּ, Job 31:12, and the like, and besides has its special ground in the metaphorical character of the cleansing. Thus, e.g., one uses Syr. 't'aa' of external misleading; but with Syr. k of moral misleading (Ewald, 217, 2); and Arab. '_ of erecting a building; but with Arab. b of the intellectual erection of a memorial (monument). It is the so-called Bâ̇âlmojâz; vid., de Sacy's Chrest Arab. i. 397. The verb מרק means in Talm. also, "to take away" (a metaph. of abstergere; cf. Arab. marak, to wipe off)
(Note: Vid., Dozy's Lettre M. Fleischer (1871), p. 198.)
and that meaning is adopted, Schabbath 33a, for the interpretations of this proverb: stripes and wounds a preparedness for evil carries away, and sorrow in the innermost part of the body, which is explained by דרוקן (a disease appearing in diverse forms; cf. "Drachenschuss,"; as the name of an animal disease); but granting that the biblical מרק may bear this meaning, the ב remains unaccountable; for we say מרק עצמו לעברה, for to prepare oneself for a transgression (sin of excess), and not בעברה. We have thus to abide by the primary meaning, and to compare the proverb, Berachoth 5a: "afflictive providences wash away all the transgressions of a man." But the proverb before us means, first at least, not the wounds which God inflicts, but those which human educational energy inflicts: deep-cutting wounds, i.e., stern discipline, leads to the rubbing off of evil, i.e., rubs it, washes it, cleanses it away. It may now be possible that in 30b the subject idea is permutatively continued: et verbera penetralium corporis (thus the Venet.: πληγαὶ τῶν ταμιείων τοῦ γαρστρός), i.e., quorum vis ad intimos corporis et animi recessus penetrat (Fleischer). But that is encumbered, and חדרי־בטן (cf. Proverbs 20:27, Proverbs 18:8), as referring to the depths to which stern corporal discipline penetrates, has not its full force. וּמכּות is either a particip.: and that is touching (ferientes) the inner chambers of the body, or חדרי־בטן is with the ב, or immediately the second object of תמריק to be supplied: and strokes (rub off, cleanse, make pure) the innermost part. Jerome and the Targ. also supply ב, but erroneously, as designating place: in secretioribus ventris, relatively better the lxx and Syr.: εἰς ταμιεῖα κοιλίας. Luther hits the sense at least, for he translates:
One must restrain evil with severe punishment,
And with hard strokes which one feels.

The blueness - Grievous wounds, which make men black and blue; or severe punishments. Cleanseth - Are the means to reclaim a wicked man, and to purge out his corruption. The belly - Of the heart. Grievous wounds or stripes cleanse not only the outward man by keeping it from evil actions, but even the inward man, by expelling or subduing vile affections: which is a great and blessed benefit of afflictions.