Ata' bin al-Sa'ib (may Allah have mercy on him) relates: Something was bequeathed through me for Banu Hashim, so I came to Abu Ja'far in Madinah. He sent me to a woman of Banu Hashim, a daughter of Sayyiduna Ali (may Allah be pleased with him), who was very old. And (there) it was related: A freed slave of the Messenger of Allah (peace and blessings be upon him), who was called Tahman or Dhakwan, told me that the Messenger of Allah (peace and blessings be upon him) said: "Charity (sadaqah) is not lawful for me nor for the people of my household, and the mawla of a people is counted as one of them."
Hadith Referenceالمعجم الكبير للطبراني / باب الذال / 4202