Does a transaction (buying or selling) performed by a financially incompetent person (*safih*) become valid if his guardian grants permission?

Primary text

There are two primary opinions regarding the validity of a transaction undertaken by a financially incompetent person (*safih*) with the permission of his guardian. One opinion holds that the transaction is valid because it is a reciprocal contract (*'aqd mu'awadah*), and the incompetent person gains authority over it through permission, analogous to marriage. Another supporting argument is that since the incompetent person is deemed rational but restricted, his disposition becomes valid through permission, similar to a child. This view asserts that if permission were invalidated, there would be no means to ascertain or test the incompetent person's eventual maturity and sound judgment.