The Prophet ﷺ said, "The mukatab is paid blood-money in proportion to what he has paid of his contract."
حدثنا عفان حدثنا وهيب حدثنا أيوب عن عكرمة
عن النبي ﷺ قال يودى المكاتب بقدر ما أدى
Its isnad is sahih. Ikrima is the freed slave of Ibn Abbas and he is trustworthy, despite those who criticized him. Bukhari said in al-Kabir 49/1/4, "There is not one among our companions who did not cite Ikrima as evidence." Abu Zura claimed that his narration from Ali is disconnected, as mentioned in al-Marasil by Ibn Abu Hatim, 58–59, but this statement is merely an assertion. What matters for the soundness of a narration, beyond trustworthiness and precision, is contemporaneity, and Ikrima was given as a gift by his master Husayn bin Abu Hurr Anbari to Ibn Abbas when Ali appointed him governor of Basra. Ali appointed Ibn Abbas over Basra in the year 36, as mentioned in Tarikh Tabari 5/224, so Ikrima was contemporary with Ali for four years or more while he was a slave belonging to Ibn Abbas, the cousin of Ali, and he was still a young man at that time, for he died, according to the more correct view, in the year 105 at the age of 80, as his daughter reported. So his age at the time of Ali's murder was 15 years.This hadith was also narrated by Bayhaqi, 10/325–326, via Affan, and he faulted it for being disconnected, and he spoke about it at length. Abu Dawud narrated something similar in meaning via Hammad bin Salama, from Ayub, from Ikrima, from Ibn Abbas. Then he pointed to this isnad and said, "It was narrated from Ayub, from Ikrima, from Ali, from the Prophet ," while Hammad bin Zayd and Ismail narrated it as disconnected, from Hammad, from Ayub, from Ikrima, from the Prophet, and Ismail bin Ulaya made it a saying of Ikrima rather than a hadith. None of this constitutes a valid criticism of the hadith. Wahib is trustworthy, prolific in hadith, and a reliable authority, so his narration should not be faulted merely because someone else transmitted the hadith in disconnected form.Ibn Hazm pointed out in al-Ihkam, 7/199, that this hadith is sahih both as narrated from Ali and as narrated from Ibn Abbas, and he elaborated on this in al-Muhalla, 9/227–228. See also Nayl al-Awtar, 6/217–219. The hadith of Ibn Abbas will come later at 2356, 2660, 3423, and 3489, and something close in meaning will also come for Ibn Abbas at 1944 and 1984.The word is "yudi" (without hamza), from diyah (blood money), meaning, if he is killed, his blood money is that of a free man in proportion to what he had paid off of his manumission contract, and the price of a slave is assessed based on what still remains owed of the price of his freedom. In ح and ه, and in most printed books, it appears as "yuaddi" with a hamza, which is an error.