Proverbs 16:21-23

Amplified Bible

²¹ 
The wise in heart will be called understanding,
And sweet speech increases persuasiveness and learning [in both speaker and listener].
²² 
Understanding (spiritual insight) is a [refreshing and boundless] wellspring of life to those who have it,
But to give instruction and correction to fools is foolishness.
²³ 
The heart of the wise instructs his mouth [in wisdom]
And adds persuasiveness to his lips.