Sahih
Al Bukhari
صحيح البخاري
Fighting for the Cause of Allah (Jihaad)
كتاب الجهاد والسير
Chapter 13: Practising good deeds before taking part in a battle
بَابُ عَمَلٌ صَالِحٌ قَبْلَ الْقِتَالِ
Sahih Al Bukhari 2808
Narrated Al-Bara
A man whose face was covered with an iron mask (i.e. clad in armor) came to the Prophet (ﷺ) and said, "O Allah's Messenger! Shall I fight or embrace Islam first? "The Prophet (ﷺ) said, "Embrace Islam first and then fight." So he embraced Islam, and was martyred. Allah's Messenger (ﷺ) said, A Little work, but a great reward. "(He did very little (after embracing Islam), but he will be rewarded in abundance).
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ الرَّحِيمِ، حَدَّثَنَا شَبَابَةُ بْنُ سَوَّارٍ الْفَزَارِيُّ، حَدَّثَنَا إِسْرَائِيلُ، عَنْ أَبِي إِسْحَاقَ، قَالَ سَمِعْتُ الْبَرَاءَ ـ رضى الله عنه ـ يَقُولُ أَتَى النَّبِيَّ صلى الله عليه وسلم رَجُلٌ مُقَنَّعٌ بِالْحَدِيدِ فَقَالَ يَا رَسُولَ اللَّهِ أُقَاتِلُ وَأُسْلِمُ. قَالَ " أَسْلِمْ ثُمَّ قَاتِلْ ". فَأَسْلَمَ ثُمَّ قَاتَلَ، فَقُتِلَ، فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " عَمِلَ قَلِيلاً وَأُجِرَ كَثِيرًا ".