Obligatory Charity Tax (Zakat)
Bukhari :: Book 2 :: Volume 24 :: Hadith 504
Narrated Abu Huraira:
The Prophet (p.b.u.h) said, "Seven people will be shaded by Allah under His shade on the day when there will be no shade except His. They are:
(1) a just ruler;
(2) a young man who has been brought up in the worship of Allah, (i.e. worship Allah (Alone) sincerely from his childhood),
(3) a man whose heart is attached to the mosque (who offers the five compulsory congregational prayers in the mosque);
(4) two persons who love each other only for Allah's sake and they meet and part in Allah's cause only;
(5) a man who refuses the call of a charming woman of noble birth for an illegal sexual intercourse with her and says: I am afraid of Allah;
(6) a person who practices charity so secretly that his left hand does not know what his right hand has given (i.e. nobody knows how much he has given in charity).
(7) a person who remembers Allah in seclusion and his eyes get flooded with tears."