Sahih Bukhari Volume 3, Book 47, Hadith Number 750.

Narated By Abu Huraira : Whenever a meal was brought to Allah’s Apostle, he would ask whether it was a gift or Sadaqa (something given in charity). If he was told that it was Sadaqa, he would tell his companions to eat it, but if it was a gift, he would hurry to share it with them.