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.  

قَالَ النَّبِيُّ ﷺ مَنْ أَعْتَقَ شَقِيصًا فِي مَمْلُوكِهِ فَعَلَيْهِ أَنْ يُعْتِقَهُ كُلَّهُ إِنْ كَانَ لَهُ مَالٌ وَإِلاَّ اسْتُسْعِيَ الْعَبْدُ غَيْرَ مَشْقُوقٍ عَلَيْهِ  

If anyone emancipates his share in a slave, he is to be completely emancipated by his money if he has money. But if he has no money, a fair price for the slave should be fixed, and the slave is required to work for his master according to the proportion of his price, but he must not be overburdened. Abu Dawud said: In the version of both the narrators the words are "he will be required to work and must not be overburdened". This is the version of 'Ali.  

عَنْ رَسُولِ اللَّهِ ﷺ قَالَ مَنْ أَعْتَقَ شِقْصًا لَهُ أَوْ شَقِيصًا لَهُ فِي مَمْلُوكٍ فَخَلاَصُهُ عَلَيْهِ فِي مَالِهِ إِنْ كَانَ لَهُ مَالٌ فَإِنْ لَمْ يَكُنْ لَهُ مَالٌ قُوِّمَ الْعَبْدُ قِيمَةَ عَدْلٍ ثُمَّ اسْتُسْعِيَ لِصَاحِبِهِ فِي قِيمَتِهِ غَيْرَ مَشْقُوقٍ عَلَيْهِ  

The tradition mentioned above by Rawh b. 'Ubadah from Sa'id b. Abu 'Arubah. In this version he did not mention the words "the slave should be required to work." If has also been transmitted by Jarir b. Hazim and Musa b. Khalaf from Qatadah through the chain of Yazid b. Zurai' and to the same effect. In this version they mentioned the words "the slave should be required to work"  

عَنْ قَتَادَةَ بِإِسْنَادِ يَزِيدَ بْنِ زُرَيْعٍ وَمَعْنَاهُ وَذَكَرَا فِيهِ السِّعَايَةَ