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.
Sahih Muslim Book 20, Hadith 29
← Previous Hadith A Muslim who emancipates a Muslim (slave). Allah will save from Fire every limb of his for every limb (of the slave). Sa'id b. Marjana said: When I heard this hadith from Abu Huraira (Allah be pleased with him), I went away and made a mention of it to 'Ali b. Husain and he at once emancipated the slave for which Ibn ja'far was prepared to pay ten thousand dirhams or one thousand dinars.

Sahih Muslim Book 20, Hadith 28 Next Hadith → A hadith like this has been narrated on the authority of Suhail with the same chain of transmitters.

Sahih Muslim Book 20, Hadith 30