Narrated Ibn 'Abbas:
That the Prophet (ﷺ) said: When the penalty (of blood money) goes to a Mukatab, or an inheritance, then he inherits in accordance with as much as he is freed from it. And the Prophet (ﷺ) said: The Mukatab is given the blood-money of a free person in accordance to what he has paid (for his freedom), and that of a slave in accordance to what remains.
[He said:] There is something on this from Umm Salamah.
[Abu 'Eisa said:] The Hadith of Ibn 'Abbas is a Hasan Hadith. This is how it was reported from Yahya bin Abi Kathir from 'Ikrimah, from Ibn 'Abbas, from the Prophet (ﷺ).
Khalid bin Al-Hadh-dha' reported it from 'Ikrimah, from 'Ali as his saying.
This is acted upon according to some of the people of knowledge among the Companions of the Prophet (ﷺ) and others.
Most of the people of knowledge among the Companions of the Prophet (ﷺ) and others said that the Mukatab remains a slave as long as he still owes a Dirham. This is the view of Sufyan Ath-Thawri, Ash-Shafi'i, Ahmad, and Ishaq.