Is the purchase by an unpermitted slave using his personal liability or borrowing valid?

Chapter on Selling the Musarrah (Animal with milk retained in udder)

Al-Mughni

Book of Sales

Book 12 · Issue 2 · Bab 5

Open in Qurani

Primary text

There are two possibilities regarding the slave's purchase using funds due from his liability or through borrowing. One possibility is that it is invalid because the slave is restrained, resembling a fool (safeeh). The other possibility is that it is valid because the restraint is for the right of others, similar to a bankrupt person or a sick person.

Supporting text

The validity of these transactions forms the basis for whether the seller or lender can recover their funds, whether from the remaining property held by the slave or the master, or by claiming the value or equivalent if the property is destroyed.