The Prophet ﷺ said, "Whoever frees his share, or his portion, or his stake in a slave, if he has enough wealth to cover the slave's full value at a fair price, the slave is fully freed. Otherwise, only the portion he freed is free."Ayub said, Nafi would sometimes say in this hadith, "meaning, only the portion he freed becomes free."
حدثنا أحمد بن منيع حدثنا إسمعيل بن إبراهيم عن أيوب عن نافع
عن النبي ﷺ قال من أعتق نصيبا أو قال شقصا أو قال شركا له في عبد فكان له من المال ما يبلغ ثمنه بقيمة العدل فهو عتيق وإلا فقد عتق منه ما عتق قال أيوب وربما قال نافع في هذا الحديث يعني فقد عتق منه ما عتق
Agreed upon. Muslim, The Book of Oaths, chapter on one who frees his share in a slave, hadith no. 1501/49, after hadith no. 1667, from the hadith of Ismail bin Ulaya. And Bukhari, hadith no. 2491, from the hadith of Ayub Sakhtiyani, through the same chain.