John Trapp on Proverbs 16:23

Verſ. 23. The heart of the wiſe teacheth his mouth] Frameth his ſpeech for him, and ſeaſoneth it with ſalt of grace, ere it ſets it, as a diſh before the hearers. Neſcit paenitenda loqui qui proferenda prius ſuo tradidit examini, ſaith Caſſiodere. Lib. 10. Ep. 4. Hee cannot lightly ſpeak amiſs, that weighs his words before hee utters them. The voice which is made in the mouth, is nothing ſo melodious as that which comes from the depth of the breaſt. Heart-ſprung ſpeech hath weight and worth in it.

And addeth learning to his lips] By reſtraining talkativeneſs, and making him as willing to hear as to ſpeak, to learn as to teach, to bee an Auditour as an Oratour.