Sahih Muslim Book 5, Hadith Number 2212.

Chapter : Exhortation to Sadaqa even though it is half a date, or a good word. for they are protection against fire.

Abu Huraira reported Allah’s Messenger (may peace be upon him) as saying: No one gives Sadaqa of a date out of his honest earning, but Allah accepts it with His Right Hand, and then fosters it as one of you fosters the colt or a young she-camel, till it becomes like a mountain or even greater.