Sahih al-Bukhari, Volume 3, Book 44, Hadith 671 (USC-MSA) ⓘ
Narrated Nafi`: Ibn `Umar said, "Allah's Messenger 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 Nafi` or the Prophet.)
حَدَّثَنَا عِمْرَانُ بْنُ مَيْسَرَةَ، حَدَّثَنَا عَبْدُ الْوَارِثِ، حَدَّثَنَا أَيُّوبُ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ أَعْتَقَ شِقْصًا لَهُ مِنْ عَبْدٍ ـ أَوْ شِرْكًا أَوْ قَالَ نَصِيبًا ـ 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 صلى الله عليه وسلم.
also referenced under: Book 47, Hadith 9 (In-Book) & Hadith 2491 (DarusSalam)