Proverbs 16:23

The heart of the wise teacheth his mouth
That is, a man that is wise in heart, as in ( Proverbs 16:21 ) ; his heart will teach his mouth what to say, when to say it, and before whom; it will prompt him to matter, that he shall not be at a loss what to say, nor how to say; it will furnish him with words and things; out of the abundance of the heart the mouth speaketh, ( Matthew 12:34 ) ; and addeth learning to his lips:
so that he does not deliver out mere words, but solid learning along with them, instructive to himself and others. The Targum is,

``and by his lips he addeth doctrine;''

or increases knowledge.