Musnad Ahmad 30:2144

'Affan narrated to us, Hammad narrated to us, he said: Muhammad ibn Ziyad informed us, he said: I heard Abu Hurairah saying: The Messenger of Allah (peace and blessings of Allah be upon him) was brought some dates from the dates of charity. He gave an order regarding them. Then he carried al-Hasan or al-Husayn upon his shoulder, and his saliva began to flow upon him. He looked at him, and behold, he was chewing a date. So he moved his cheek and said: "Spit it out, O my son, spit it out, O my son. Do you not realize that the family of Muhammad do not eat charity?"