كتاب الجهاد والسير
32  
The Book of Jihad and Expeditions
(25)
Chapter: Permissibility of eating food seized as booty in Dar Al-Harb
(25)
باب أَخْذِ الطَّعَامِ مِنْ أَرْضِ الْعَدُوِّ ‏‏
Sahih Muslim 1772 a

It has been narrated on the authority of Abdullah b. Mughaffal who said I found a bag containing fat on the day of the Battle of Khaibar. I caught hold of it and said:

I will not give anything today from it to anybody. Then I turned round and saw that the Messenger of Allah (ﷺ) was smiling (at my words).
حَدَّثَنَا شَيْبَانُ بْنُ فَرُّوخَ، حَدَّثَنَا سُلَيْمَانُ، - يَعْنِي ابْنَ الْمُغِيرَةِ - حَدَّثَنَا حُمَيْدُ، بْنُ هِلاَلٍ عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، قَالَ أَصَبْتُ جِرَابًا مِنْ شَحْمٍ يَوْمَ خَيْبَرَ - قَالَ - فَالْتَزَمْتُهُ فَقُلْتُ لاَ أُعْطِي الْيَوْمَ أَحَدًا مِنْ هَذَا شَيْئًا - قَالَ - فَالْتَفَتُّ فَإِذَا رَسُولُ اللَّهِ صلى الله عليه وسلم مُتَبَسِّمًا ‏.‏
Reference : Sahih Muslim 1772a
In-book reference : Book 32, Hadith 86
USC-MSA web (English) reference : Book 19, Hadith 4377
  (deprecated numbering scheme)