Hadith 11:10
Abu Huraira reported God's Messenger as saying, “A son does not repay what he owes his father unless he buys him and emancipates him if he finds him in slavery.” Muslim transmitted it.
وَعَنْ أَبِي هُرَيْرَةَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «لَا يَجْزِي وَلَدٌ وَالِده إِلَّا أَن يجده مَمْلُوكا فيشتر بِهِ فيعتقه» . رَوَاهُ مُسلم
Original Reference: Mishkat al-Masabih 3391