Abu Hurairah reported the Prophet ﷺ as saying:
If anyone emancipates a share in his slave, he should completely emancipate him if he has money; but if he has none, then slave will be required to work (to pay for his freedom), but he must not be overburdened.

حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا أَبَانُ، - يَعْنِي الْعَطَّارَ - حَدَّثَنَا قَتَادَةُ، عَنِ النَّضْرِ بْنِ أَنَسٍ، عَنْ بَشِيرِ بْنِ نَهِيكٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ النَّبِيُّ ﷺ " مَنْ أَعْتَقَ شَقِيصًا فِي مَمْلُوكِهِ فَعَلَيْهِ أَنْ يُعْتِقَهُ كُلَّهُ إِنْ كَانَ لَهُ مَالٌ وَإِلاَّ اسْتُسْعِيَ الْعَبْدُ غَيْرَ مَشْقُوقٍ عَلَيْهِ " .