Sunan an-Nasai Book 45, Hadith 4722

أَخْبَرَنَا مُحَمَّدُ بْنُ الْعَلاَءِ، وَأَحْمَدُ بْنُ حَرْبٍ، - وَاللَّفْظُ لأَحْمَدَ - قَالاَ حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قُتِلَ رَجُلٌ عَلَى عَهْدِ رَسُولِ اللَّهِ صلى الله عليه وسلم فَرُفِعَ الْقَاتِلُ إِلَى النَّبِيِّ صلى الله عليه وسلم فَدَفَعَهُ إِلَى وَلِيِّ الْمَقْتُولِ فَقَالَ الْقَاتِلُ يَا رَسُولَ اللَّهِ لاَ وَاللَّهِ مَا أَرَدْتُ قَتْلَهُ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم لِوَلِيِّ الْمَقْتُولِ ‏ "‏ أَمَا إِنَّهُ إِنْ كَانَ صَادِقًا ثُمَّ قَتَلْتَهُ دَخَلْتَ النَّارَ ‏"‏ ‏.‏ فَخَلَّى سَبِيلَهُ ‏.‏ قَالَ وَكَانَ مَكْتُوفًا بِنِسْعَةٍ فَخَرَجَ يَجُرُّ نِسْعَتَهُ فَسُمِّيَ ذَا النِّسْعَةِ ‏.‏

It was narrated that Abu Hurairah said:"A man was killed during the time of the Messenger of Allah, and the Killer was brought to the Prophet. He handed him over to the heir of the victim, but the killer said: 'O Messenger of Allah, by Allah I did not means to kill him.' The Messenger of Allah said to the next of kin: 'If he is telling the truth and you kill him, you will go to the Fire.' So he let him go. He had been tied with a string and he went out dragging his string, so he became known as Dhul-Nis'ah (the one with the string)