Proverbs 17:28 in the World English Bible
Even a fool, when he keeps silent, is counted wise. When he shuts his lips, he is thought to be discerning.
Context
27 He that hath knowledge spareth his words: and a man of understanding is of an excellent spirit.
28 Even a fool, when he holdeth his peace, is counted wise: and he that shutteth his lips is esteemed a man of understanding.