Sahih Muslim Book 19, Hadith Number 4378.

Chapter : Justification for taking food in the land of the enemy.

This tradition has been transmitted by a different chain of narrators with a different wording, the last in the chain being the same narrator, (i.e. ‘Abdullah b. Mughaffal), who said: A bag containing food and fat was thrown to us. I left forward to catch it. Then I turned round and saw (to my surprise) the Messenger of Allah (may peace be upon him) and I felt ashamed of my act in his presence.