What does Proverbs 16:21 mean?

The phrase "wise of heart," as used here, suggests both factual and emotional discernment. A person recognized for their knowledge has a good reputation (Proverbs 3:3–4). Even more influential, however, is the person who pairs that discernment with carefully considered loving words (Proverbs 15:1). The same Hebrew word used for "sweetness" here is also employed later in reference to a honeycomb (Proverbs 16:24). The same idea is highlighted in two other proverbs in this passage (Proverbs 16:23–24). Truth spoken in gentler tones and phrases tends to be more easily accepted.

Of course, the wisest teacher was Jesus. He was always able to discern the heart and minds of others and provide perfect answers. Christians ought to follow Jesus' example and use wise, pleasant words. Of course, this does not preclude all use of cutting phrases or rebuke (Matthew 12:33; 23:37). Those are best used with caution, however, and part of godly wisdom is knowing when to take such steps. Colossians 3:16 exhorts: "Let the word of Christ dwell in you richly, teaching and admonishing one another in all wisdom, singing psalms and hymns and spiritual songs, with thankfulness in your hearts to God." Colossians 4:6 says, "Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer each person."