Mishkat al-Masabih 13 Marriage كتاب النكاح 258

وَعَنْ أَبِي هُرَيْرَةَ قَالَ: قَالَ رَسُولُ اللَّهِ صلى الله عَلَيْهِ وَسلم: «للمملوك طَعَامه وَكسوته وَلَا يُكَلف من الْعَمَل إِلَّا مَا يُطيق» . رَوَاهُ مُسلم

Abu Huraira reported God’s Messenger as saying, “A slave is entitled to his food and clothing, and he should have imposed on him only such work as he is capable of doing.” Muslim transmitted it.