Though thou shouldest bray a fool in a mortar among wheat with a pestle, yet will not his foolishness depart from him.

Jamieson-Fausset-Brown Bible Commentary

22. The obstinate wickedness of such is incurable by the heaviest inflictions.

Matthew Henry's Concise Commentary

27:15,16. The contentions of a neighbour may be like a sharp shower, troublesome for a time; the contentions of a wife are like constant rain. 17. We are cautioned to take heed whom we converse with. And directed to have in view, in conversation, to make one another wiser and better. 18. Though a calling be laborious and despised, yet those who keep to it, will find there is something to be got by it. God is a Master who has engaged to honour those who serve him faithfully. 19. One corrupt heart is like another; so are sanctified hearts: the former bear the same image of the earthly, the latter the same image of the heavenly. Let us carefully watch our own hearts, comparing them with the word of God. 20. Two things are here said to be never satisfied, death and sin. The appetites of the carnal mind for profit or pleasure are always desiring more. Those whose eyes are ever toward the Lord, are satisfied in him, and shall for ever be so. 21. Silver and gold are tried by putting them into the furnace and fining-pot; so is a man tried by praising him. 22. Some are so bad, that even severe methods do not answer the end; what remains but that they should be rejected? The new-creating power of God's grace alone is able to make a change. 23-27. We ought to have some business to do in this world, and not to live in idleness, and not to meddle with what we do not understand. We must be diligent and take pains. Let us do what we can, still the world cannot be secured to us, therefore we must choose a more lasting portion; but by the blessing of God upon our honest labours, we may expect to enjoy as much of earthly blessings as is good for us.