KILLER AND THE KILLED H H 395 "The Prophet, praise and peace be upon him, sent a Muslim army against an unbelieving community, and they fought against each other. There was one unbeliever in particular who was very skillful. One of the Muslims - it was said that it was most likely Osama, the son of Zaid - was looking for an opportunity to kill this unbeliever. When he raised his sword over him, the unbeliever cried out: 'There is no god except Allah.' Yet the Muslim killed him. When the news of the victory reached the Prophet, praise and peace be upon him, he was also informed of this incident. He sent for the Muslim and inquired: 'Why did you kill him?' He replied: 'O Messenger of Allah, praise and peace be upon him, he created havoc among the Muslims, killing several of them, so and so, so and so, etc. When I advanced against him and he saw my sword he exclaimed: 'There is no god except Allah.' The Prophet, praise and peace be upon him, asked: 'Did you kill him?' He replied: 'Yes.' The Prophet, praise and peace be upon him, said: 'On the Day of Judgement, what will you do to his witnessing: There is no god except Allah?' He asked: 'O Messenger of Allah, praise and peace be upon him, supplicate for forgiveness for me.' But the Prophet, praise and peace be upon him, kept repeating without changing: 'What will you do to his witnessing: There is no god except Allah on the Day of Judgement?'" R 395 Muslim with a chain up to Jundab, the son of Abdullah who related this.
394- وعن جندب بن عبد الله رضي الله عنه : أنَّ رَسُول الله صلى الله عليه وآله وسلم بَعَثَ بَعْثاً مِنَ المُسْلِمينَ إِلَى قَومٍ مِنَ المُشرِكينَ ، وَأنَّهُمْ التَقَوْا ، فَكَانَ رَجُلٌ مِنَ المُشْركينَ إِذَا شَاءَ أنْ يَقْصِدَ إِلَى رَجُل مِنَ المُسْلِمينَ قَصَدَ لَهُ فَقَتَلَهُ ، وَأنَّ رَجُلاً مِنَ المُسْلِمِينَ قَصَدَ غَفْلَتَهُ . وَكُنَّا نتحَدَّثُ أنَّهُ أُسَامَةُ بْنُ زَيْدٍ ، فَلَمَّا رَفَعَ عَلَيهِ السَّيفَ ، قَالَ : لا إلهَ إلاَّ اللهُ ، فَقَتَلهُ ، فَجَاءَ البَشيرُ إِلَى رَسُول الله صلى الله عليه وآله وسلم فَسَألَهُ وَأخبَرَهُ ، حَتَّى أخْبَرَهُ خَبَرَ الرَّجُلِ كَيْفَ صَنَعَ ، فَدَعَاهُ فَسَألَهُ ، فَقَالَ : "لِمَ قَتَلْتَهُ ؟" فَقَالَ : يَا رَسُول اللهِ ، أوْجَعَ في المُسلِمِينَ ، وَقَتَلَ فُلاناً وفلاناً ، وسمى لَهُ نَفراً ، وَإنِّي حَمَلْتُ عَلَيهِ ، فَلَمَّا رَأى السَّيفَ ، قَالَ : لا إلهَ إلاَّ اللهُ . قَالَ رَسُول الله صلى الله عليه وآله وسلم : "أقَتَلْتَهُ ؟" قَالَ : نَعَمْ . قَالَ : "فَكَيفَ تَصْنَعُ بلاَ إلهَ إلاَّ اللهُ ، إِذَا جَاءتْ يَوْمَ القِيَامَةِ ؟" قَالَ : يَا رَسُول الله ، اسْتَغْفِرْ لِي . قَالَ : "وكَيفَ تَصْنَعُ بِلا إلهَ إلاَّ الله إِذَا جَاءتْ يَوْمَ القِيَامَةِ ؟" فَجَعَلَ لاَ يَزِيدُ عَلَى أنْ يَقُولَ : "كَيفَ تَصْنَعُ بِلا إلهَ إلاَّ الله إِذَا جَاءتْ يَوْمَ القِيَامَةِ" رواه مسلم .