Sunan an Nasai
2612
Sahih+2

It was narrated from Ihn Abi Rafi, from his father, that:the Messenger of Allah appointed a man from Banu Makhzum to collect Sadaqah. Abu Rafi wanted to go with him, but the Messenger of Allah said: "The Sadaqah is not permissible for us, and the freed slave of a people is one of them

SahihAbu Ghuddah
SahihAl-Albani