Bahz bin Hakim narrates from his father, from his grandfather (may Allah be pleased with him), that when something was brought to the Prophet (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 that it was a gift, he (peace and blessings be upon him) would take it, and if it was said that it was charity, he would say to the Companions (may Allah be pleased with them): "Take it."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الصدقات / 13250