What is the ruling on imposing a financial fine on a borrower if they are late in returning books beyond the specified period?

It is permissible to lend books and anything that can be benefited from while its substance remains. If the borrower delays returning the loaned item beyond the agreed-upon time without an excuse, they incur sin thereby. It is permissible for the lender to take an amount equivalent to the rental value of the book if the borrower does not return the loaned item on time. It is also permissible to impose a fine on the person who delays returning the book if this was agreed upon in advance. This fine may be more or less than the equivalent rental value, as long as both parties have consented to it and the borrower entered into the agreement with full knowledge.