Mishkat al-Masabih 14 Emancipation كتاب العتق 8

وَعَنْ أَبِي هُرَيْرَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «مَنْ أَعْتَقَ شِقْصًا فِي عَبْدٍ أُعْتِقَ كُلُّهُ إِنْ كَانَ لَهُ مَالٌ فَإِنْ لَمْ يَكُنْ لَهُ مَالٌ اسْتَسْعَى الْبعد غير مشقوق عَلَيْهِ»

Abu Huraira reported the Prophet as saying, “If anyone emancipates a share in a slave, he is to be completely emancipated if he has money; but if he has none, the slave will be required to work to pay for his freedom, but must not be overburdened.” (Bukhari and Muslim.)