Performing good deeds and experiencing a clear conscience benefits the physical and mental health of the giver.

Original passage

Good deeds are twice a blessing, benefiting both the giver and the receiver of the kindness. The consciousness of right-doing is one of the best medicines for diseased bodies and minds. When the mind is free and happy from a sense of duty well done and the satisfaction of giving happiness to others, the cheering, uplifting influence brings new life to the whole being.