Sahih Bukhari Volume 003, Book 042, Hadith Number 612.

Narated By Anas : The Prophet passed a date fallen on the way and said, "Were I not afraid that it may be from a Sadaqa (charitable gifts), I would have eaten it.

"Narrated Abu Huraira: The Prophet said, "Sometimes when I return home and find a date fallen on my bed, I pick it up in order to eat it, but I fear that it might be from a Sadaqa, so I throw it."