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كتاب الجهاد والسير
56  
Fighting for the Cause of Allah (Jihaad)
(142)
Chapter: Providing the prisoners of war with clothes
(142)
باب الْكِسْوَةِ لِلأُسَارَى
Sahih al-Bukhari 3008

Narrated Jabir bin `Abdullah:

When it was the day (of the battle) of Badr, prisoners of war were brought including Al-Abbas who was undressed. The Prophet (ﷺ) looked for a shirt for him. It was found that the shirt of `Abdullah bin Ubai would do, so the Prophet (ﷺ) let him wear it. That was the reason why the Prophet (ﷺ) took off and gave his own shirt to `Abdullah. (The narrator adds, "He had done the Prophet (ﷺ) some favor for which the Prophet liked to reward him.")

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ، حَدَّثَنَا ابْنُ عُيَيْنَةَ، عَنْ عَمْرٍو، سَمِعَ جَابِرَ بْنَ عَبْدِ اللَّهِ ـ رضى الله عنهما ـ قَالَ لَمَّا كَانَ يَوْمَ بَدْرٍ أُتِيَ بِأُسَارَى، وَأُتِيَ بِالْعَبَّاسِ وَلَمْ يَكُنْ عَلَيْهِ ثَوْبٌ، فَنَظَرَ النَّبِيُّ صلى الله عليه وسلم لَهُ قَمِيصًا فَوَجَدُوا قَمِيصَ عَبْدِ اللَّهِ بْنِ أُبَىٍّ يَقْدُرُ عَلَيْهِ، فَكَسَاهُ النَّبِيُّ صلى الله عليه وسلم إِيَّاهُ، فَلِذَلِكَ نَزَعَ النَّبِيُّ صلى الله عليه وسلم قَمِيصَهُ الَّذِي أَلْبَسَهُ‏.‏ قَالَ ابْنُ عُيَيْنَةَ كَانَتْ لَهُ عِنْدَ النَّبِيِّ صلى الله عليه وسلم يَدٌ فَأَحَبَّ أَنْ يُكَافِئَهُ‏.‏
Reference : Sahih al-Bukhari 3008
In-book reference : Book 56, Hadith 217
USC-MSA web (English) reference : Vol. 4, Book 52, Hadith 252
  (deprecated numbering scheme)