Albert Barnes Commentary Proverbs 10:21

"The lips of the righteous feed many; But the foolish die for lack of understanding." — Proverbs 10:21 (ASV)

Feed - The Hebrew word, like poimainein — includes the idea of guiding as well as nourishing; doing a shepherd’s work in both.

For want of wisdom - Some prefer, through him who lacks understanding, referring to a person. The wise guides others to safety; the fool, empty-headed, and empty-hearted, involves others like himself in destruction.