Is it valid to use a borrowed slave as collateral for an amount greater than what the lender authorized?
General Chapter
Al-Mughni
Book of Loan for Use
Primary text
If the slave is used as collateral for a greater amount than specified by the lender, the collateralization is invalid. This is because the one who consents to be bound by a specific amount of debt is not necessarily obligated to consent to a greater amount.
Supporting text
If the slave is used as collateral for a lesser amount than authorized, the transaction is valid. This is based on the principle that whoever accepts ten, implicitly accepts less than ten, similar to someone who orders an item to be bought at a certain price but buys it for less.