Sahih Bukhari Volume 5, Book 64, Hadith 4341

حَدَّثَنِي مَحْمُودٌ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا مَعْمَرٌ، وَحَدَّثَنِي نُعَيْمٌ، أَخْبَرَنَا عَبْدُ اللَّهِ، أَخْبَرَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنْ سَالِمٍ، عَنْ أَبِيهِ، قَالَ بَعَثَ النَّبِيُّ صلى الله عليه وسلم خَالِدَ بْنَ الْوَلِيدِ إِلَى بَنِي جَذِيمَةَ، فَدَعَاهُمْ إِلَى الإِسْلاَمِ فَلَمْ يُحْسِنُوا أَنْ يَقُولُوا أَسْلَمْنَا‏.‏ فَجَعَلُوا يَقُولُونَ صَبَأْنَا، صَبَأْنَا‏.‏ فَجَعَلَ خَالِدٌ يَقْتُلُ مِنْهُمْ وَيَأْسِرُ، وَدَفَعَ إِلَى كُلِّ رَجُلٍ مِنَّا أَسِيرَهُ، حَتَّى إِذَا كَانَ يَوْمٌ أَمَرَ خَالِدٌ أَنْ يَقْتُلَ كُلُّ رَجُلٍ مِنَّا أَسِيرَهُ فَقُلْتُ وَاللَّهِ لاَ أَقْتُلُ أَسِيرِي، وَلاَ يَقْتُلُ رَجُلٌ مِنْ أَصْحَابِي أَسِيرَهُ، حَتَّى قَدِمْنَا عَلَى النَّبِيِّ صلى الله عليه وسلم فَذَكَرْنَاهُ، فَرَفَعَ النَّبِيُّ صلى الله عليه وسلم يَدَهُ فَقَالَ ‏"‏ اللَّهُمَّ إِنِّي أَبْرَأُ إِلَيْكَ مِمَّا صَنَعَ خَالِدٌ ‏"‏‏.‏ مَرَّتَيْنِ‏.‏

Narrated By Salim's father : The Prophet sent Khalid bin Al-Walid to the tribe of Jadhima and Khalid invited them to Islam but they could not express themselves by saying, "Aslamna (i.e. we have embraced Islam)," but they started saying "Saba'na! Saba'na (i.e. we have come out of one religion to another)." Khalid kept on killing (some of) them and taking (some of) them as captives and gave every one of us his Captive. When there came the day then Khalid ordered that each man (i.e. Muslim soldier) should kill his captive, I said, "By Allah, I will not kill my captive, and none of my companions will kill his captive." When we reached the Prophet, we mentioned to him the whole story. On that, the Prophet raised both his hands and said twice, "O Allah! I am free from what Khalid has done."