It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that some young men of Banu Hashim came to the Prophet (peace and blessings be upon him) and said: O Messenger of Allah! Appoint us to collect this charity (sadaqah); we will receive from it what people receive, and we will discharge (the duty) as they discharge it. He (peace and blessings be upon him) said: "Charity is not lawful for us, the family of Muhammad; it is the dirt of people. But what do you think: when I take hold of the ring (of the door) of Paradise, will I give anyone preference over you?"
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11024