It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that dates of charity were brought to the Messenger of Allah (peace and blessings be upon him) from the people's harvests. People began presenting their own dates until a heap of dates had gathered with him. Hasan bin Ali (may Allah be pleased with him) was playing with those dates; he picked up a date and ate it. The Prophet (peace and blessings be upon him) took it out of his mouth and threw it away, then said: "Do you not know that the family of Muhammad do not eat charity?"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الصدقات / 13232