Obligatory Charity Tax (Zakat)
Bukhari :: Book 2 :: Volume 24 :: Hadith 485
Narrated Abu Huraira:
The Prophet said, "(On the Day of Resurrection) camels will come to their owner in the best state of health they have ever had (in the world), and if he had not paid their Zakat (in the world) then they would tread him with their feet; and similarly, sheep will come to their owner in the best state of health they have ever had in the world, and if he had not paid their Zakat, then they would tread him with their hooves and would butt him with their horns." The Prophet added, "One of their rights is that they should be milked while water is kept in front of them." The Prophet added, "I do not want anyone of you to come to me on the Day of Resurrection, carrying over his neck a sheep that will be bleating. Such a person will (then) say, 'O Muhammad! (please intercede for me,) I will say to him. 'I can't help you, for I conveyed Allah's Message to you.' Similarly, I do not want anyone of you to come to me carrying over his neck a camel that will be grunting. Such a person (then) will say "O Muhammad! (please intercede for me)." I will say to him, "I can't help you for I conveyed Allah's message to you."