Ibn ʿUmar said, "Messenger of Allah ﷺ said, 'If one manumits his share of a jointly possessed slave, and can afford the price of the other shares according to the adequate price of the slave, the slave will be completely manumitted; otherwise he will be partially manumitted.' " (Aiyub, a sub-narrator is not sure whether the saying " ... otherwise he will be partially manumitted" was said by Nafiʿ or the Prophet.)  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ أَعْتَقَ شِقْصًا لَهُ مِنْ عَبْدٍ أَوْ شِرْكًا أَوْ قَالَ نَصِيبًا وَكَانَ لَهُ مَا يَبْلُغُ ثَمَنَهُ بِقِيمَةِ الْعَدْلِ فَهْوَ عَتِيقٌ وَإِلاَّ فَقَدْ عَتَقَ مِنْهُ مَا عَتَقَ قَالَ لاَ أَدْرِي قَوْلُهُ عَتَقَ مِنْهُ مَا عَتَقَ قَوْلٌ مِنْ نَافِعٍ أَوْ فِي الْحَدِيثِ عَنِ النَّبِيِّ ﷺ  

The Prophet ﷺ said, "Whoever manumits his share of a jointly possessed slave, it is imperative for him to get that slave manumitted completely by paying the remaining price, and if he does not have sufficient money to manumit him, then the price of the slave should be estimated justly, and he is to be allowed to work and earn the amount that will manumit him (without overburdening him)".  

عَنِ النَّبِيِّ ﷺ قَالَ مَنْ أَعْتَقَ شَقِيصًا مِنْ مَمْلُوكِهِ فَعَلَيْهِ خَلاَصُهُ فِي مَالِهِ فَإِنْ لَمْ يَكُنْ لَهُ مَالٌ قُوِّمَ الْمَمْلُوكُ قِيمَةَ عَدْلٍ ثُمَّ اسْتُسْعِيَ غَيْرَ مَشْقُوقٍ عَلَيْهِ