The Prophet ﷺ said, "The slave under a contract for emancipation is freed in proportion to what he has paid. The prescribed punishment is applied to him in proportion to what has been freed of him, and he inherits in proportion to what has been freed of him."
أخبرنا محمد بن عيسى بن النقاش قال حدثنا يزيد يعني ابن هارون قال أنبأنا حماد عن قتادة عن خلاس عن علي وعن أيوب عن عكرمة
عن النبي ﷺ قال المكاتب يعتق بقدر ما أدى ويقام عليه الحد بقدر ما عتق منه ويرث بقدر ما عتق منه
No references are available.
[Sahih], and it is in Kubra, hadith: 7014. Hammad is Ibn Salama, and the following hadith is a corroborating witness for this hadith, being the hadith of Ayub from Ikrima from Ibn Abbas. Abu Dawud narrated it, hadith: 4582, and Tirmidhi graded it hasan, hadith: 1359.