1 tn Heb “a shrewd man” (so NAB); KJV, NIV “a prudent man”; NRSV “One who is clever.”
sn A shrewd person knows how to use knowledge wisely, and restrains himself from revealing all he knows.
2 sn The term כֹּסֶה (koseh, “covers; hides”) does not mean that he never shares his knowledge, but discerns when it is and is not appropriate to speak.
3 tn Heb “the heart of fools.” The term לֵב (lev, “heart”) functions as a synecdoche of part (= heart) for the whole (= person): “foolish people.” This type of fool despises correction and instruction. His intent is to proclaim all that he does – which is folly. W. McKane says that the more one speaks, the less likely he is able to speak effectively (Proverbs [OTL], 422). Cf. TEV “stupid people advertise their ignorance”; NLT “fools broadcast their folly.”
4 sn The noun אִוֶּלֶת (’ivvelet, “foolishness; folly”) is the antithesis of perception and understanding. It is related to the noun אֱוִּיל (’evvil, “fool”), one who is morally bad because he despises wisdom and discipline, mocks at guilt, is licentious and quarrelsome, and is almost impossible to rebuke.
