Is it permissible to open the door of lending from a library endowed by a benefactor in the mosque, knowing that the endower's condition was not to remove the books from it, and that the lack of lending has reduced people's benefit from it?

Scholars differed regarding the permissibility of disposing of an endowment contrary to the endower's condition. The preponderant opinion allows this for an overriding benefit. Therefore, there is no objection to lending books in exchange for a guarantee or similar measure that ensures their safe return.