Musannaf Ibn Abi Shayba 13:1899

Abu Bakr narrated to us, he said: Hafs narrated to us, from Ash'ath, from al-Hasan, who said: If he was wealthy, he would be liable [for the debt/damages], and the right of patronage (al-wala') would belong to him. If he was insolvent, the slave would work to pay it off, and the right of patronage would be shared between them.