Musnad Ahmad 30:2185

Muhammad ibn Ja'far narrated to us, he said: Shu'bah narrated to us, from Muhammad ibn Ziyad, from Abu Hurairah, that al-Hasan took a date from the dates of the charity and put it in his mouth. The Messenger of Allah, peace and blessings of Allah be upon him, said to him: "Kakh, kakh! Throw it away. Do you not realize that we do not eat charity?"