(21) Folly.—Shown in wasted opportunities, and the commission of evil (Proverbs 10:23), while the “man of understanding” directs his way in accordance with the will of God.

15:16,17. Believers often have enough when worldly eyes see little; the Lord is with them, without the cares, troubles, and temptations which are with the wealth of the wicked. 18. He that is slow to anger, not only prevents strife, but appeases it, if kindled. 19. Those who have no heart to their work, pretend that they cannot do their work without hardship and danger. And thus many live always in doubt about their state, because always in neglect of some duty. 20. Those who treat an aged mother or a father with contempt or neglect, show their own folly. 21. Such as are truly wise, study that their thoughts, words, and actions should be regular, sincere, and holy. 22. If men will not take time and pains to deliberate, they are not likely to bring any thing to pass. 23. Wisdom is needed to suit our discourse to the occasions. 24. A good man sets his affections on things above; his way leads directly thither.i. e., The empty-hearted, rejoicing in folly, goes the wrong way; the man of understanding, rejoicing in wisdom, goes the right way. 21. walketh uprightly—and so finds his joy (Pr 3:6; 10:23). Is joy; he doth not only work wickedness, but taketh pleasure in it.

Walketh uprightly, Heb. directeth or maketh straight his going, i.e. ordereth all his actions by the rule of God’s word, and delighteth in so doing, which is understood from the opposite clause.

Folly is joy to him that is destitute of wisdom,.... Or "that wants a heart" (q), a wise and understanding one; by "folly" is meant sin, for all sin is folly; and that is very pleasing and joyous to a wicked he chooses it and delights in it; instead of being ashamed of it, and sorry for it, he glories in it, and makes his boast of it; and not only takes pleasure in committing it himself, but also in those that do it; see Proverbs 10:23;

but a man of understanding walketh uprightly; he who has his understanding enlightened by the Spirit of God; who has an understanding given him by the Son of God; who has a spiritual and experimental understanding of the Gospel, and the truths of it: he walks according to the rule of the divine word; he walks as he has Christ for an example, and by faith on him; and after the spirit, and not after the flesh: or "directs himself in walking" (r), his goings, as the Vulgate Latin version, according to the above rule, example, and guidance, by the assistance of the spirit and grace of God; otherwise it is not in man that walketh of himself to direct his steps, Jeremiah 10:23.

(q) "carenti corde", Montanus; "ei qui deficitur", Schultens. (r) "diriget seipsum ambulando", Montanus; "diriget ambulare, vel ad ambulandum", Vatablus; "diriget viam suam ad ambulandum", Mercerus, Gejerus.

Folly is joy to him that is destitute of wisdom: but a man of understanding walketh uprightly.