Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him) said: On the day of Khaybar I found a bag of fat, which I kept with me, and I said: I will not give anyone any of this. I turned around and saw that the Messenger of Allah (peace and blessings be upon him) was smiling.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19154