Albert Barnes Commentary Proverbs 10:20

"The tongue of the righteous is [as] choice silver: The heart of the wicked is little worth." — Proverbs 10:20 (ASV)

The tongue, the instrument of the mind, is contrasted with the heart or mind itself; the just with the wicked; and choice silver with the worthless "little," the Hebrew word for "little" possibly being taken in its primary sense as a "filing" or "scraping" of dross or worthless metal. If the tongue is precious, how much more the mind! If the heart is worthless, how much more the speech!