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."  

أَنَّ رَسُولَ اللَّهِ ﷺ اسْتَعْمَلَ رَجُلاً مِنْ بَنِي مَخْزُومٍ عَلَى الصَّدَقَةِ فَأَرَادَ أَبُو رَافِعٍ أَنْ يَتْبَعَهُ فَقَالَ رَسُولُ اللَّهِ ﷺ إِنَّ الصَّدَقَةَ لاَ تَحِلُّ لَنَا وَإِنَّ مَوْلَى الْقَوْمِ مِنْهُمْ