Sahih Bukhari Volume 009, Book 086, Hadith Number 088.
Narrated By Talha bin 'Ubaidullah : A bedouin with unkempt hair came to Allah's Apostle and said, "O Allah's Apostle! Tell me what Allah has enjoined on me as regards prayers." The Prophet said, "You have to offer perfectly the five (compulsory) prayers in a day and a night (24 hrs.), except if you want to perform some extra optional prayers." The bedouin said, "Tell me what Allah has enjoined on me as regards fasting." The Prophet said, "You have to observe fast during the month of Ramadan except if you fast some extra optional fast." The bedouin said, "Tell me what Allah has enjoined on me as regard Zakat." The Prophet then told him the Islamic laws and regulations whereupon the bedouin said, "By Him Who has honored you, I will not perform any optional deeds of worship and I will not leave anything of what Allah has enjoined on me." Allah's Apostle said, "He will be successful if he has told the truth (or he will enter Paradise if he said the truth)." And some people said, "The Zakat for one-hundred and twenty camels is two Hiqqas, and if the Zakat payer slaughters the camels intentionally or gives them as a present or plays some other trick in order to avoid the Zakat, then there is no harm (in it) for him.