كتاب الأيمان
27  
The Book of Oaths
(12)
Chapter: One who frees his share in a slave
(12)
باب مَنْ أَعْتَقَ شِرْكًا لَهُ فِي عَبْدٍ ‏‏
Sahih Muslim 1501 e

'Abdullah b. 'Umar reported Allah's Messenger (ﷺ) as saying:

He who gives up his share in a slave, and he has money enough to meet the full price, a fair price for him should be fixed; otherwise be has emancipated him to the extent that he has emancipated.
وَحَدَّثَنَا شَيْبَانُ بْنُ فَرُّوخَ، حَدَّثَنَا جَرِيرُ بْنُ حَازِمٍ، عَنْ نَافِعٍ، مَوْلَى عَبْدِ اللَّهِ بْنِ عُمَرَ عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ مَنْ أَعْتَقَ نَصِيبًا لَهُ فِي عَبْدٍ فَكَانَ لَهُ مِنَ الْمَالِ قَدْرُ مَا يَبْلُغُ قِيمَتَهُ قُوِّمَ عَلَيْهِ قِيمَةَ عَدْلٍ وَإِلاَّ فَقَدْ عَتَقَ مِنْهُ مَا عَتَقَ ‏"‏ ‏.‏
Reference : Sahih Muslim 1501e
In-book reference : Book 27, Hadith 74
USC-MSA web (English) reference : Book 15, Hadith 4104
  (deprecated numbering scheme)