Sahih Muslim Book - 28, Hadith - 4388

وَحَدَّثَنِى مُحَمَّدُ بْنُ حَاتِمٍ حَدَّثَنَا سَعِيدُ بْنُ سُلَيْمَانَ حَدَّثَنَا هُشَيْمٌ أَخْبَرَنَا إِسْمَاعِيلُ بْنُ سَالِمٍ عَنْ عَلْقَمَةَ بْنِ وَائِلٍ عَنْ أَبِيهِ قَالَ أُتِىَ رَسُولُ اللَّهِ -صلى الله عليه وسلم- بِرَجُلٍ قَتَلَ رَجُلاً فَأَقَادَ وَلِىَّ الْمَقْتُولِ مِنْهُ فَانْطَلَقَ بِهِ وَفِى عُنُقِهِ نِسْعَةٌ يَجُرُّهَا فَلَمَّا أَدْبَرَ قَالَ رَسُولُ اللَّهِ -صلى الله عليه وسلم- « الْقَاتِلُ وَالْمَقْتُولُ فِى النَّارِ ». فَأَتَى رَجُلٌ الرَّجُلَ فَقَالَ لَهُ مَقَالَةَ رَسُولِ اللَّهِ -صلى الله عليه وسلم- فَخَلَّى عَنْهُ. قَالَ إِسْمَاعِيلُ بْنُ سَالِمٍ فَذَكَرْتُ ذَلِكَ لِحَبِيبِ بْنِ أَبِى ثَابِتٍ فَقَالَ حَدَّثَنِى ابْنُ أَشْوَعَ أَنَّ النَّبِىَّ -صلى الله عليه وسلم- إِنَّمَا سَأَلَهُ أَنْ يَعْفُوَ عَنْهُ فَأَبَى.

It was narrated from 'Alqamah bin Wa'il that his father said: "A man who had killed another man was brought to the Messenger of Allah (s.a.w) by the heir of the one who had been killed, and (the Messenger of Allah (s.a.w) gave the heir the right to retaliate). He took him away with a rope around his neck by which he was leading him. When he left, the Messenger of Allah (s.a.w) said: 'The killer and the slain are both in Hell' A man went to that man and told him what the Messenger of Allah (s.a.w) had said, so he let him go." Isma'il bin Salim said: "I mentioned that to Habib bin Abi Thabit and he said: 'Ibn Ashwa' told me that the Prophet (s.a.w) asked him to let him go and he refused."'