Sahih Bukhari
Lost Things Picked up by Someone (Luqaata)
Volume: 003 / Book Number: 042 / Hadith Number: 612
Narrated 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."