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كتاب الجهاد والسير
56  
Fighting for the Cause of Allah (Jihaad)
(80)
Chapter: The shield, and shielding oneself with the shield of his companion
(80)
باب الْمِجَنِّ وَمَنْ يَتَتَرَّسُ بِتُرْسِ صَاحِبِهِ
Sahih al-Bukhari 2904

Narrated `Umar:

The properties of Bani An-Nadir which Allah had transferred to His Apostle as Fai Booty were not gained by the Muslims with their horses and camels. The properties therefore, belonged especially to Allah's Messenger (ﷺ) who used to give his family their yearly expenditure and spend what remained thereof on arms and horses to be used in Allah's Cause.

حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنِ الزُّهْرِيِّ، عَنْ مَالِكِ بْنِ أَوْسِ بْنِ الْحَدَثَانِ، عَنْ عُمَرَ ـ رضى الله عنه ـ قَالَ كَانَتْ أَمْوَالُ بَنِي النَّضِيرِ مِمَّا أَفَاءَ اللَّهُ عَلَى رَسُولِهِ صلى الله عليه وسلم مِمَّا لَمْ يُوجِفِ الْمُسْلِمُونَ عَلَيْهِ بِخَيْلٍ وَلاَ رِكَابٍ، فَكَانَتْ لِرَسُولِ اللَّهِ صلى الله عليه وسلم خَاصَّةً، وَكَانَ يُنْفِقُ عَلَى أَهْلِهِ نَفَقَةَ سَنَتِهِ، ثُمَّ يَجْعَلُ مَا بَقِيَ فِي السِّلاَحِ وَالْكُرَاعِ، عُدَّةً فِي سَبِيلِ اللَّهِ‏.‏
Reference : Sahih al-Bukhari 2904
In-book reference : Book 56, Hadith 118
USC-MSA web (English) reference : Vol. 4, Book 52, Hadith 153
  (deprecated numbering scheme)