Sunan al-Nasa'i
The Book of Oaths (qasamah), Retaliation and Blood Money — Hadith #4865
أَخْبَرَنَا أَحْمَدُ بْنُ عَمْرِو بْنِ السَّرْحِ، قَالَ حَدَّثَنَا ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي يُونُسُ بْنُ يَزِيدَ، عَنِ ابْنِ شِهَابٍ، قَالَ قَرَأْتُ كِتَابَ رَسُولِ اللَّهِ صلى الله عليه وسلم الَّذِي كَتَبَ لِعَمْرِو بْنِ حَزْمٍ حِينَ بَعَثَهُ عَلَى نَجْرَانَ - وَكَانَ الْكِتَابُ عِنْدَ أَبِي بَكْرِ بْنِ حَزْمٍ - فَكَتَبَ رَسُولُ اللَّهِ صلى الله عليه وسلم " هَذَا بَيَانٌ مِنَ اللَّهِ وَرَسُولِهِ { يَا أَيُّهَا الَّذِينَ آمَنُوا أَوْفُوا بِالْعُقُودِ } " . وَكَتَبَ الآيَاتِ مِنْهَا حَتَّى بَلَغَ { إِنَّ اللَّهَ سَرِيعُ الْحِسَابِ } ثُمَّ كَتَبَ " هَذَا كِتَابُ الْجِرَاحِ فِي النَّفْسِ مِائَةٌ مِنَ الإِبِلِ " . نَحْوَهُ .
“I read the letter of the Messenger of allah which he wrote for ‘Amr bin Hazm when he sent him to govern Najran. The letter was with Abu Bakr bin Hazm. The Messenger of Allah wrote this; ‘A statement from Allah and His Messenger; O you who believe! Fulfill (your) obligations, and he wrote the Verses until he reached. Verily, Allah is Swift in reckoning. Then he wrote: ‘this is the book if retaliation: For a soul, one hundred camels, ”” and so on
Chain of Narration (Isnad)