Ibn 'Umar reported Allah's Messenger (ﷺ) as saying:He who emancipates his share in the slave, it is his responsibility to secure full freedom for him provided he (the slave) has enough money to pay the (remaining) price, but it he has not so much money he would be emancipated to the extent that the first man emancipated.
حَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا عُبَيْدُ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ أَعْتَقَ شِرْكًا لَهُ مِنْ مَمْلُوكٍ فَعَلَيْهِ عِتْقُهُ كُلُّهُ إِنْ كَانَ لَهُ مَالٌ يَبْلُغُ ثَمَنَهُ فَإِنْ لَمْ يَكُنْ لَهُ مَالٌ عَتَقَ مِنْهُ مَا عَتَقَ " .
Muslim
The Book of Oaths • Hadith 73