Sunan an-Nasa'i · Hadith 4808
The Book of Oaths (qasamah), Retaliation and Blood Money - كتاب القسامة
أخبرنا محمد بن المثنى، قال حدثنا وكيع، قال حدثنا علي بن المبارك، عن يحيى، عن عكرمة، عن ابن عباس، قال قضى رسول الله صلى الله عليه وسلم في المكاتب يقتل بدية الحر على قدر ما أدى .
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)."
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).