Sunan an-Nasa'i #4012 · The Book of Fighting [The Prohibition of Bloodshed]

Sunan an-Nasa'iIt was narrated from 'Ubaid bin 'Umair that
Sunan an-Nasa'i · Book 37 · The Book of Fighting [The Prohibition of Bloodshed]
Sunan an-Nasa'i · كتاب 37 · كتاب القتال [تحريم سفك الدماء]
His father - who was one of the Companions of the Prophet [SAW] - told him: "A man said: 'O Messenger of Allah, what are the major sins?' He said: 'They are seven; the most grievous of which are associating others with Allah, killing a soul unlawfully and fleeing (from the battlefield) on the day of the march.'" It is abridged
أَخْبَرَنَا الْعَبَّاسُ بْنُ عَبْدِ الْعَظِيمِ، قَالَ حَدَّثَنَا مُعَاذُ بْنُ هَانِئٍ، قَالَ حَدَّثَنَا حَرْبُ بْنُ شَدَّادٍ، قَالَ حَدَّثَنَا يَحْيَى بْنُ أَبِي كَثِيرٍ، عَنْ عَبْدِ الْحَمِيدِ بْنِ سِنَانٍ، عَنْ حَدِيثِ، عُبَيْدِ بْنِ عُمَيْرٍ أَنَّهُ حَدَّثَهُ أَبُوهُ، وَكَانَ، مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم - أَنَّ رَجُلاً قَالَ يَا رَسُولَ اللَّهِ مَا الْكَبَائِرُ قَالَ ‏
"‏ هُنَّ سَبْعٌ أَعْظَمُهُنَّ إِشْرَاكٌ بِاللَّهِ وَقَتْلُ النَّفْسِ بِغَيْرِ حَقٍّ وَفِرَارٌ يَوْمَ الزَّحْفِ ‏"‏ ‏.‏ مُخْتَصَرٌ ‏.‏
Reference : Sunan an-Nasa'i 4012In-book reference : Book 37, Hadith 47