Hadith 588
ان الله لم يرض بحكم نبي ولا غيره فى الصدقات حتي حكم فيها هو فجزاها ثمانية اجزاء
"Regarding zakat, Allah Almighty was not pleased with the command of any prophet nor with the command of anyone else, until He Himself gave the command concerning it and divided the expenditures of zakat into eight categories."