Even a smile is an act of charity
Prophet Muhammad, upon whom be peace, once said: "Charity is prescribed for each descendant of Adam every day the sun rises."
He was then asked: "From what do we give charity every day?"
The Prophet answered: "The doors of goodness are many...enjoining good, forbidding evil, removing harm from the road, listening to the deaf, leading the blind, guiding one to the object of his need, hurrying with the strength of one's legs to one in sorrow who is asking for help, and supporting the feeble with the strength of one's arms--all of these are charity prescribed for you."
He then said: "Even your smile for your brother is a charity."