A prudent man concealeth knowledge: but the heart of fools proclaimeth foolishness.
A wise man can keep his mouth shut, even when he knows more on a subject than anyone in the group. A fool cannot keep his mouth shut, even when he basically knows nothing, for his heart demands that he keep belching foolishness. Will Solomon never end his rebuke of the tongue, or are his repetitive warnings necessary for this unruly body part?
The tongue, the bodily member by which you speak, is a great source of evil and trouble. There are many verses in Proverbs and elsewhere to correct and teach you regarding your speech. There are several reasons: it is easy to form words, you can hurt others easily, you can harm yourself easily, and you discredit the Lord Jesus Christ by ungodly speech.
A prudent man is wise. He knows when to do what, and how to do it. He has knowledge, but he does not easily share it. If he knows a subject, humility keeps him from talking about it (Pr 29:11). If he knows a person’s failure, charity keeps him from spreading it (Pr 11:13). If he sees a mote in an eye, he waits until he has removed the beam from his own (Matt 7:5). If he meets scorners, he does not waste his pearls (Pr 9:8; 23:9; Matt 7:6).
A prudent man is generally a reserved man (Pr 17:27-28). He will speak when spoken to, but he will not be offering his opinion here and yon without others asking for it. He knows there is certain sin in a multitude of words, so he cuts his words in half (Pr 10:19). He knows that it is better to listen, for many reasons, than to speak (James 1:19-20). This man is easy to spot in a crowd, for he will be carefully listening more than easily talking.
But a fool has a fire in his heart that sets his tongue ablaze! This fire comes from hell (Jas 3:1-12). James spared nothing in his horrible indictment of a fool’s tongue. It is a world of iniquity, but the fool loves to use it. He is also easy to spot in a crowd, for he cannot stop talking, and his words are obnoxious chattering of folly (Eccl 10:3,12-14). Jesus helped understand the role of the heart by saying that all words come from it (Luke 6:45).
A fool is always giving his opinion, though the hearers quickly realize he does not know what he is talking about (Pr 15:28). He must talk, so he continues on to the confirmation of his great ignorance. A fool will proclaim the failures of others, for he has no power to restrain his words. He must tattle and whisper. He is happy to tell anyone about the motes in their eyes and the eyes of others, even while the barn beams seriously clutter his face.
The blessed Lord Jesus Christ was very prudent (Is 52:13). He was not a self-promoter at all (Matt 8:4; 16:20; 11:29; 12:18-21). He knew when to speak, and when not to speak, though knowing all things (Is 50:4; John 2:24-25). This combination of wisdom and reservation demonstrates His perfect character. Reader, follow His godly example, today!