Sahih Muslim #4333 · The Book of Oaths

Sahih MuslimAbu Huraira reported Allah's Apostle
Sahih Muslim · Book 27 · The Book of Oaths
Sahih Muslim · كتاب 27 · كتاب الأيمان
He who emancipates his portion in a slave, full emancipation may be secured for him out of his property (if he has money) if he has enough property to meet (the required expenses), but if he has not enough property, the slave should be put to extra labour (in order to earn money for buying his freedom), but he should not be overburdened.
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 شَقِيصًا لَهُ فِي عَبْدٍ فَخَلاَصُهُ فِي مَالِهِ إِنْ كَانَ لَهُ مَالٌ فَإِنْ لَمْ يَكُنْ لَهُ مَالٌ اسْتُسْعِيَ الْعَبْدُ غَيْرَ مَشْقُوقٍ عَلَيْهِ ‏"‏ ‏.‏
Reference : Sahih Muslim 4333In-book reference : Book 27, Hadith 80