en_tn_lite_do_not_use/pro/14/30.md

A tranquil heart

"A peaceful mindset" or "An attitude that is at peace"

rots the bones

The word "rots" represents the decay of a person and "bones" represents the whole person. AT: "causes a person to be unhealthy in body and spirit" (See: rc://en/ta/man/translate/figs-metaphor)