Proverbs 12 23
If you're sensible, you don't show off your knowledge, but stupid people announce their stupidity.
Compare with other 3 random translations
AMP Proverbs 12:23A prudent man is reluctant to display his knowledge, but the heart of [self-confident] fools proclaims their folly. [Isa. 32:6.]
EAS Proverbs 12:23Careful people keep quiet about how much they know. But foolish people show everyone how silly they are.
CSB Proverbs 12:23A shrewd person conceals knowledge, but a foolish heart publicizes stupidity.