| Barnes' Notes on the Bible Good as it is to "handle a matter wisely," it is far better to "trust in the Lord." The former is really impossible except through the latter.
Gill's Exposition of the Entire BibleHe that handleth a matter wisely shall find good,.... That frames and composes his discourse well on any subject he takes in hand; or manages his affairs prudently and discreetly, in which he is concerned; or that wisely attends to the affair of humility, as Aben Ezra: or rather to the word, that is, to the word of God; is not a careless, negligent, unconcerned hearer of the word, but a diligent and attentive one; whose heart is opened by the Spirit of God to attend to what is spoken in it; who lays it up in his heart, and makes it the rule of his conduct in life: such a man finds good things; things which are for his profit, edification, and instruction; good truths, good doctrines, good counsel and advice, good directions and instructions; promises of good things, things for his present comfort and future happiness; and whoso trusteth in the Lord, happy is he; not to his own wisdom; nor in his own strength; nor in his riches, nor righteousness; nor in the favour of men, no, not of princes; but in the Lord, and in his Word; he shall want no good thing, he is kept in perfect peace; he is in the utmost safety, is like Mount Zion, that can never be removed, Jeremiah 17:7.
Keil and Delitzsch Biblical Commentary on the Old Testament20 He that giveth heed to the word will find prosperity; And he that trusteth in Jahve, blessed is he! The "word" here is the word κατ ̓ ἐξ., the divine word, for משׂכּיל על־דּבר is the contrast of בּז לדבר, Proverbs 13:13, cf. Nehemiah 8:13. טוב is meant, as in Proverbs 17:20, cf. Proverbs 13:21, Psalm 23:6; to give heed to God's word is the way to true prosperity. But at last all depends on this, that one stand in personal fellowship with God by means of faith, which here, as at Proverbs 28:25; Proverbs 29:25, is designated after its specific mark as fiducia. The Mashal conclusion אשׁריו occurs, besides here, only at Proverbs 14:21; Proverbs 29:18.
Geneva Study BibleHe that handleth a matter wisely shall find good: and whoso trusteth in the LORD, happy is he.
Wesley's Notes 16:20 Good - He who orders his affairs with discretion.
King James Translators' Noteshandleth...: or, understandeth a matter
Scofield Reference NotesMargin trusteth See Scofield Note: "Ps 2:12".
Jamieson-Fausset-Brown Bible Commentary20. handleth a matter-wisely considers "the word," that is, of God (compare Pr 13:13). trusteth-(Compare Ps 2:12; 118:8, 9).
Matthew Henry's Concise Commentary16:12. The ruler that uses his power aright, will find that to be his best security. 13. Put those in power who know how to speak to the purpose. 14,15. Those are fools, who, to obtain the favour of an earthly prince, throw themselves out of God's favour. 16. There is joy and satisfaction of spirit, only in getting wisdom. 17. A sincerely religious man keeps at a distance from every appearance of evil. Happy is the man that walks in Christ, and is led by the Spirit of Christ. 18. When men defy God's judgments, and think themselves far from them, it is a sign they are at the door. Let us not fear the pride of others, but fear pride in ourselves. 19. Humility, though it exposes to contempt in the world, is much better than high-spiritedness, which makes God an enemy. He that understands God's word shall find good. 21. The man whose wisdom dwells in his heart, will be found more truly prudent than many who possess shining talents. 22. As waters to a thirsty land, so is a wise man to his friends and neighbours. 23. The wise man's self-knowledge, always suggests something proper to be spoken to others. 24. The word of God cures the diseases that weaken our souls. 25. This is caution to all, to take heed of deceiving themselves as to their souls. 26. We must labour for the meat which endureth to everlasting life, or we must perish.
Matthew Henry's Whole Bible CommentaryVerse 20 Note, 1. Prudence gains men respect and success: He that handles a matter wisely (that is master of his trade and makes it to appear he understands what he undertakes, that is considerate in his affairs, and, when he speaks or writes on any subject, does it pertinently) shall find good, shall come into good repute, and perhaps may make a good hand of it. 2. But it is piety only that will secure men's true happiness: Those that handle a matter wisely, if they are proud and lean to their own understanding, though they may find some good, yet they will have no great satisfaction in it; but he that trusts in the Lord, and not in his own wisdom, happy is he, and shall speed better at last. Some read the former part of the verse so as to expound it of piety, which is indeed true wisdom: He that attends to the word (the word of God, ch. 13:13) shall find good in it and good by it. And whoso trusts in the Lord, in his word which he attends to, is happy. | 
