Sahih al-Bukhari, Hadith 2522

Narrated `Abdullah bin `Umar: Allah's Messenger said, "Whoever frees his share of a common slave and he has sufficient money to free him completely, should let its price be estimated by a just man and give his partners the price of their shares and manumit the slave; otherwise (i.e. if he has not sufficient money) he manumits the slave partially."

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ مَنْ أَعْتَقَ شِرْكًا لَهُ فِي عَبْدٍ، فَكَانَ لَهُ مَالٌ يَبْلُغُ ثَمَنَ الْعَبْدِ قُوِّمَ الْعَبْدُ قِيمَةَ عَدْلٍ، فَأَعْطَى شُرَكَاءَهُ حِصَصَهُمْ وَعَتَقَ عَلَيْهِ، وَإِلاَّ فَقَدْ عَتَقَ مِنْهُ مَا عَتَقَ ‏" ‏‏.‏

sunnah.com