Does good like a medicine - Better, works a good healing. Omit “like.”

A merry heart does good like a medicine. —Or rather, Makes good a recovery. (For the duty of religious gladness,…

A merry heart does good [like] a medicine
Does the body good, makes it healthful and vigorous. Cheerfulness of spiri…

It is great mercy that God permits us to be cheerful, and cause to be cheerful, if by his grace he gives us hearts to be cheerful.