It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that whenever food was brought to the Messenger of Allah (peace and blessings be upon him), he (peace and blessings be upon him) would ask: "Is this a gift or charity?" If it was said, "It is charity," he (peace and blessings be upon him) would say to the Companions (may Allah be pleased with them): "Eat," and he would not eat himself; and if it was said, "It is a gift," he (peace and blessings be upon him) would also eat together with them.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الهبات / 12047