Sahih Bukhari
Fighting for the Cause of Allah (Jihaad)
Volume: 004 / Book Number: 052 / Hadith Number: 141
Narrated Abu Huraira:
The Prophet said, "Charity is obligatory everyday on every joint of a human being. If one helps a person in matters concerning his riding animal by helping him to ride it or by lifting his luggage on to it, all this will be regarded charity. A good word, and every step one takes to offer the compulsory Congregational prayer, is regarded as charity; and guiding somebody on the road is regarded as charity."