Proverbs 12:18, 23
Proverbs 12:18 AMP
There is one who speaks rashly like the thrusts of a sword, But the tongue of the wise brings healing.
Proverbs 12:23 AMP
A shrewd man is reluctant to display his knowledge [until the proper time], But the heart of [over-confident] fools proclaims foolishness. [Is 32:6]