The Messenger of Allah ﷺ said, "Whoever frees his share in a slave, or a portion of one, must complete the slave's emancipation from his own wealth if he has wealth. If he has no wealth, the slave is required to work to earn his remaining value, without being overburdened."
حدثنا أبو بكر بن أبي شيبة حدثنا علي بن مسهر ومحمد بن بشر عن سعيد بن أبي عروبة عن قتادة عن النضر بن أنس عن بشير بن نهيك
قال رسول الله ﷺ من أعتق نصيبا له في مملوك أو شقصا فعليه خلاصه من ماله إن كان له مال فإن لم يكن له مال استسعي العبد في قيمته غير مشقوق عليه
Bukhari related it in the Book of Partnership, chapter "Valuing Shared Property at a Fair Price," no. 2492, 2527, and Muslim in the Book of Manumission, chapter "Mentioning the Earning of the Slave (through Work)," no. 1503, from the hadith of Saeed bin Abu Aruba, through this same chain.