Sunan an-Nasa'i 4808
سنن النسائي#4808Sahihأَخْبَرَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ حَدَّثَنَا وَكِيعٌ، قَالَ حَدَّثَنَا عَلِيُّ بْنُ الْمُبَارَكِ، عَنْ يَحْيَى، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَضَى رَسُولُ اللَّهِ صلى الله عليه وسلم فِي الْمُكَاتَبِ يُقْتَلُ بِدِيَةِ الْحُرِّ عَلَى قَدْرِ مَا أَدَّى .
It was narrated that Ibn 'Abbas said:"The Messenger of Allah ruled that the Diyah for a Mukatab who is killed should be (equivalent) to the Diyah for a free mand, proportionate to the amount be had paid off (toward buying his freedom)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 45:103