The Book on Government
33/35. Chapter:
Two Men, one of whom kills the other, and both will enter Paradise
Sahih Muslim
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَزُهَيْرُ بْنُ حَرْبٍ، وَأَبُو كُرَيْبٍ قَالُوا حَدَّثَنَا وَكِيعٌ، عَنْ سُفْيَانَ، عَنْ أَبِي الزِّنَادِ، بِهَذَا الإِسْنَادِ مِثْلَهُ .
The same tradition has been narrated on the authority of Abu Zinad (with the same chain of transmitters).
Reference : Sahih Muslim 1890bIn-book reference : Book 33, Hadith 189USC-MSA web (English) reference : Book 20, Hadith 4659