It was narrated from 'Abdullah bin Abi Qatadah that his father said:"A man came to the Prophet (ﷺ) when he was on the Minbar and said: 'O Messenger of Allah, do you think that if I wield this sword of mine in the cause of Allah, with patience and seeking reward, facing the enemy, and not running away, will Allah forgive my sins?' He said: 'Yes.' When he turned away, he called him back and said: 'Jibril says: unless you are in debt.'"
أَخْبَرَنَا عَبْدُ الْجَبَّارِ بْنُ الْعَلاَءِ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرٍو، سَمِعَ مُحَمَّدَ بْنَ قَيْسٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي قَتَادَةَ، عَنْ أَبِيهِ، قَالَ جَاءَ رَجُلٌ إِلَى النَّبِيِّ صلى الله عليه وسلم وَهُوَ عَلَى الْمِنْبَرِ فَقَالَ يَا رَسُولَ اللَّهِ أَرَأَيْتَ إِنْ ضَرَبْتُ بِسَيْفِي فِي سَبِيلِ اللَّهِ صَابِرًا مُحْتَسِبًا مُقْبِلاً غَيْرَ مُدْبِرٍ حَتَّى أُقْتَلَ أَيُكَفِّرُ اللَّهُ عَنِّي خَطَايَاىَ قَالَ " نَعَمْ " . فَلَمَّا أَدْبَرَ دَعَاهُ فَقَالَ " هَذَا جِبْرِيلُ يَقُولُ إِلاَّ أَنْ يَكُونَ عَلَيْكَ دَيْنٌ " .
Nesai
The Book of Jihad • Hadith 3158