Musnad Abu Ya'la al-Mawsili 111:116

Zuhayr narrated to us, Muhammad ibn Abd Allah al-Asadi narrated to us, Sufyan narrated to us, from Ibn Abi Layla, from al-Hakam, from Miqsam, from Ibn Abbas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) sent Arqam ibn Abi al-Arqam al-Zuhri to collect some of the charity (sadaqah). He passed by Abu Rafi and asked him to accompany him. He (Abu Rafi) came to the Prophet (peace and blessings of Allah be upon him) and mentioned that to him. He (the Prophet) said: "O Abu Rafi, indeed the charity is forbidden for Muhammad and for the family of Muhammad, and the freed slave (mawla) of a people is from them, or from themselves."