The Book of Zakat (Kitab Al-Zakat)
Muslim :: Book 5 : Hadith 2204
Hammam b. Munabbih reported that-this is out of (those ahadith) which Abu Huraira narrated to us from Muhammad, the Messenger of Allah (may peace be upon him). And he while making a mention of ahadith reported from Allah's Messenger (may peace be upon him) said this: Sadaqa is due on every joint of a person, every day the sun rises. Administering of justice between two men is also a Sadaqa. And assisting a man to ride upon his beast, or helping him load his luggage upon it, is a Sadaqa; and a good word is a Sadaqa; and every step that you take towards prayer is a Sadaqa, and removing of harmful things from the pathway is a Sadaqa.