John Trapp Complete Commentary
Proverbs 21:15
Proverbs 21:15 [It is] joy to the just to do judgment: but destruction [shall be] to the workers of iniquity.
Ver. 15. It is joy to the just to do judgment.] They love it dearly, and therefore cannot but rejoice in it exceedingly: "I rejoice at thy word, as one that findeth great spoil," Psa 119:162 wherein the pleasure is usually as much as the profit. Besides, as every flower hath its sweet savour, so every good duty carries meat in the mouth - comfort in the performance. Hence the saints' alacrity in God's service, so far as they are spiritual. "I delight in the law of God, after the inward man," saith St Paul, Rom 7:22 who yet but a little before complained of a clog.
But destruction shall be to the workers of iniquity.] Wicked men are great workmen; they put themselves to no small pains in "catering for the flesh to fulfil the lusts thereof"; yea, and this they do with singular delight, as the opposition implies; they "weary themselves to commit iniquity," Jer 9:5 and yet they give not over, but lie grinding day and night in the mill of some or other base lust. Now what can come of this, better than utter destruction? which indeed is the just hire of the least sin, and will befall the workers of iniquity, as sure as the coat is on their back or the heart in their body.