Matthew Henry and continuators on Proverbs 14:33

33 Wisdom resteth in the heart of him that hath understanding: but that which is in the midst of fools is made known.

Observe, 1. Modesty is the badge of wisdom. He that is truly wise hides his treasure, so as not to boast of it (Matt. xiii. 44), though he does not hide his talent, so as not to trade with it. His wisdom rests in his heart; he digests what he knows, and has it ready to him, but does not unseasonably talk of it and make a noise with it. The heart is the seat of the affections, and there wisdom must rest in the practical love of it, and not swim in the head. 2. Openness and ostentation are a mark of folly. If fools have a little smattering of knowledge, they take all occasions, though very foreign, to produce it, and bring it in by head and shoulders. Or the folly that is in the midst of fools is made known by their forwardness to talk. Many a foolish man takes more pains to show his folly than a wise man thinks it worth his while to take to show his wisdom.