وَحَدَّثَنِي عَمْرٌو النَّاقِدُ، حَدَّثَنَا إِسْمَاعِيلُ بْنُ إِبْرَاهِيمَ، عَنِ ابْنِ أَبِي عَرُوبَةَ، عَنْ قَتَادَةَ، عَنِ النَّضْرِ بْنِ أَنَسٍ، عَنْ بَشِيرِ بْنِ نَهِيكٍ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏"‏ مَنْ أَعْتَقَ شِقْصًا لَهُ فِي عَبْدٍ فَخَلاَصُهُ فِي مَالِهِ إِنْ كَانَ لَهُ مَالٌ فَإِنْ لَمْ يَكُنْ لَهُ مَالٌ اسْتُسْعِيَ الْعَبْدُ غَيْرَ مَشْقُوقٍ عَلَيْهِ ‏"‏ ‏.‏

Abu Huraira (Allah be pleased witli him) reported Allah's Prophet (PBUH) as saying: If anyone emancipates a share in a slave, he is to be completely emancipated if he has money; but if he has none, the slave will be required to work to pay for his freedom, but must not be over-burhened. Translation Not Available

Book reference: Sahih Muslim Book 20 Hadith 3581
Web reference: Sahih Muslim Book 9 Hadith 1503 a