Sahih Bukhari
Obligatory Charity Tax (Zakat)
Volume: 002 / Book Number: 024 / Hadith Number: 576
Narrated Abu Humaid Al-Sa'idi:
Allah's Apostle (p.b.u.h) appointed a man called Ibn Al-Lutbiya, from the tribe of Al-Asd to collect Zakat from Bani Sulaim. When he returned, (after collecting the Zakat) the Prophet checked the account with him.