Narrated Anas (Radi-Allahu 'anhu):
That Abu Bakr wrote for him, Zakat regulations which Allah's Apostle (Sallallahu 'Alaihi Wa Sallam) had made compulsory, and wrote that one should neither collect various portions (of the property) nor divide the property into various portions in order to avoid paying Zakat.
Bukhari Vol. 9 : No. 87