Sahih Bukhari Volume 9, Book 89, Hadith Number 305.

Narrated By Abu Humaid As-Sa’idi : The Prophet employed Ibn Al-Utbiyya to collect Zakat from Bani Sulaim, and when he returned (with the money) to Allah’s Apostle the Prophet called him to account, and he said, “This (amount) is for you, and this was given to me as a present.” Allah’s Apostle said, “Why don’t you stay at your father’s house or your mother’s house to see whether you will be given gifts or not, if you are telling the truth?” Then Allah’s Apostle stood up and addressed the people, and after glorifying and praising Allah, he said: Amma Ba’du (then after) I employ some men from among you for some job which Allah has placed in my charge, and then one of you comes to me and says, ‘This (amount) is for you and this is a gift given to me.’ Why doesn’t he stay at the house of his father or the house of his mother and see whether he will be given gifts or not if he was telling the truth by Allah, none of you takes anything of it (i.e., Zakat) for himself (Hisham added: unlawfully) but he will meet Allah on the Day of Resurrection carrying it on his neck! I do not want to see any of you carrying a grunting camel or a mooing cow or a bleating sheep on meeting Allah.” Then the Prophet raised both his hands till I saw the whiteness of his armpits, and said, “(No doubt)! Haven’t I conveyed Allah’s Message!”