Proverbs 16:21

New English Translation

²¹The one who is wise in heart^[a] is called^[b] discerning,
and kind speech^[c] increases persuasiveness.^[d]

Proverbs 16:21 tn Heb “wise of heart” (so NRSV).
Proverbs 16:21 tn Heb “to the wise of heart it will be called discerning.” This means that the wise of heart, those who make wise decisions (“heart” being the metonymy), will gain a reputation of being the discerning ones.
Proverbs 16:21 tn Heb “sweetness of lips.” The term “lips” is a metonymy of cause, meaning what is said. It is a genitive of specification. The idea of “sweetness” must be gracious and friendly words. The teaching will be well-received because it is both delightful and persuasive (cf. NIV “pleasant words promote instruction”).
Proverbs 16:21 tn Heb “teaching” or “receptivity”; KJV “learning”; NIV “instruction.”

New English Translation (NET)