Human speech is a powerful, double-edged force. It can serve as a tool to grow eternal truth, or it can act as a destructive, distorting weapon that ultimately leads to ruin.
The primary approach among commentators is that the speech of a righteous person naturally produces fruits of wisdom and morality. By avoiding idle chatter, a good person dedicates his voice to teaching knowledge and guiding others toward what is right [עמנואל הרומי, מצודת דוד]. This kind of wisdom is permanent, eternal, and true; it stands on its own and never contradicts itself [רלב״ג]. Furthermore, there is a distinct difference between someone who merely learns rules and a truly righteous individual. The righteous person has fully absorbed this wisdom through practical life experience. As a result, his speech becomes a natural spring, constantly offering the correct answer and practical advice tailored to any specific situation [מלבי״ם].
In sharp contrast stands the distorting tongue of those who speak lies and twist the truth, actively overturning the wisdom of the Torah [רלב״ג, ביאור שטיינזלץ, מצודת דוד]. Sometimes, these individuals are cynics who use clever wordplay to manipulate the sincere words of the righteous. They mock innocence and encourage others to chase after material success rather than spiritual devotion [אלשיך]. Others might use philosophical arguments to attack the paths of faith [מלבי״ם].
However, this deceitful speech is doomed to be cut off. Because lies are inherently inconsistent and lack any real foundation, they simply cannot survive the test of time [רלב״ג, ביאור שטיינזלץ]. This ultimate silencing is viewed as a natural consequence, a fitting punishment, or even a specific curse placed upon liars by King Solomon [עמנואל הרומי].
Understanding this ongoing struggle between the two types of speech offers a powerful message of encouragement. A righteous person might fear that his words will be manipulated or mocked by those looking for a fight, but he must never remain silent. He is urged to continue sharing his wisdom for the public good. He can do so with the clear confidence that his genuine life experience will ultimately triumph over any twisted arguments, and that the lying tongue will eventually be silenced and bear its own guilt [אלשיך, מלבי״ם].