"Whoever frees a portion" or, he said: "a part" or he said: "a share he owns of a slave, then he can afford the remainder of the price according to the reasonable price, then he will be free. Otherwise he has freed as much as he has freed (only)." Ayyub (one of the narrators) said: "Perhaps Nafi said in this Hadith: 'Meaning he has freed as much of him as he has freed.'"
حَدَّثَنَا أَحْمَدُ بْنُ مَنِيعٍ، حَدَّثَنَا إِسْمَاعِيلُ بْنُ إِبْرَاهِيمَ، عَنْ أَيُّوبَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ مَنْ أَعْتَقَ نَصِيبًا - أَوْ قَالَ شِقْصًا أَوْ قَالَ شِرْكًا لَهُ فِي عَبْدٍ فَكَانَ لَهُ مِنَ الْمَالِ مَا يَبْلُغُ ثَمَنَهُ بِقِيمَةِ الْعَدْلِ فَهُوَ عَتِيقٌ وَإِلاَّ فَقَدْ عَتَقَ مِنْهُ مَا عَتَقَ . قَالَ أَيُّوبُ وَرُبَّمَا قَالَ نَافِعٌ فِي هَذَا الْحَدِيثِ يَعْنِي فَقَدْ عَتَقَ مِنْهُ مَا عَتَقَ . قَالَ أَبُو عِيسَى حَدِيثُ ابْنِ عُمَرَ حَدِيثٌ حَسَنٌ صَحِيحٌ وَقَدْ رَوَاهُ سَالِمٌ عَنْ أَبِيهِ عَنِ النَّبِيِّ صلى الله عليه وسلم نَحْوَهُ .
Tirmizi
The Chapters On Judgements From The Messenger of Allah • Hadith 1358