Proverbs 14:30 New English Translation

³⁰A tranquil spirit^[a] revives the body,^[b]
but envy^[c] is rottenness to the bones.^[d]

Proverbs 14:30 tn Heb “heart of calmness” or “heart of healing.” The term לֵב (lev, “heart, mind”) is a metonymy for the emotional state of a person (BDB 660 s.v. 6). The genitive noun מַרְפֵּא (marpeʾ) functions as an attributive adjective and may be one of two homonyms. 1 מַרְפֵּא (“healing”) derives from the root רָפָא (raphaʾ, “to heal”) and 2 מַרְפֵּא (“calmness, gentleness”) derives from the root רָפָה (raphah, “to be slack, loose”). A healthy spirit is tranquil, bringing peace to the body (J. H. Greenstone, Proverbs, 158).
Proverbs 14:30 tn Heb “is the life of the flesh” (so KJV, ASV); NAB, NIV “gives life to the body.”
Proverbs 14:30 tn The term קִנְאָה (qinʾah, “envy”) refers to passionate zeal or “jealousy” (so NAB, NCV, TEV, NLT), depending on whether the object is out of bounds or within one’s rights. In the good sense one might be consumed with zeal to defend the institutions of the sanctuary. But as envy or jealousy the word describes an intense and sometimes violent excitement and desire that is never satisfied.
Proverbs 14:30 tn Heb “rottenness of bones.” The term “bones” may be a synecdoche representing the entire body; it is in contrast with “flesh” of the first colon. One who is consumed with envy finds no tranquility or general sense of health in body or spirit.

New English Translation (NET)