The tongue of the just is as choice silver: the heart of the wicked is little worth.
– Proverbs 10:20
[S]olomon contrasts the tongue of the just with the heart of the wicked—righteous speech with the mind of the ungodly. A man’s speech is produced from the heart as if the heart were a treasure trove (Luke 6:45). Good treasure means good words and evil treasure means evil words. Little worth indicates smallness. It is scarcity in the bad sense because the fool produces a multitude of words but scarcely any are good (Proverbs 15:28). Choice silver is scarce in the good sense that makes it rare, valuable, and precious. It is also aesthetically pleasing, or pleasantly beautiful (Proverbs 25:11-12).