Proverbs 16:23

Teacheth his mouth; directeth him what, and when, and how to speak, and keepeth him from speaking rashly and foolishly. Addeth learning to his lips, i.e. enableth him to speak learnedly and wisely. Or, increaseth learning (in himself and others) by (as this Hebrew particle oft signifies, and is by some rendered here) his lips, i.e. by his wise speeches; that this may agree with the latter clause of Proverbs 16:21, where this same phrase is used.