A son does not repay what he owes his father unless he buys him (the father) in case he is a slave and then emancipates him. In the narration transmitted by Ibn Abu Shaiba there is a slight change of words.  

قَالَ رَسُولُ اللَّهِ ﷺ لاَ يَجْزِي وَلَدٌ وَالِدًا إِلاَّ أَنْ يَجِدَهُ مَمْلُوكًا فَيَشْتَرِيَهُ فَيُعْتِقَهُ وَفِي رِوَايَةِ ابْنِ أَبِي شَيْبَةَ وَلَدٌ وَالِدَهُ  

A hadith like this has been narrated on the authority of Suhail with the same chain of transmitters.  

عَنْ سُهَيْلٍ بِهَذَا الإِسْنَادِ مِثْلَهُ وَقَالُوا وَلَدٌ وَالِدَهُ