Allah's Apostle said, There is a (compulsory) Sadaqa (charity) to be ...

Hadith 4:232

Narrated Abu Huraira:

Allah's Apostle said, "There is a (compulsory) Sadaqa (charity) to be given for every joint of the human body (as a sign of gratitude to Allah) everyday the sun rises. To judge justly between two persons is regarded as Sadaqa, and to help a man concerning his riding animal by helping him to ride it or by lifting his luggage on to it, is also regarded as Sadaqa, and (saying) a good word is also Sadaqa, and every step taken on one's way to offer the compulsory prayer (in the mosque) is also Sadaqa and to remove a harmful thing from the way is also Sadaqa."