Who has the authority to place a restriction (Hajr) upon an improvident person (Safīh)?

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The restriction upon the improvident person is only to be imposed by the ruler (Hākim). This is the opinion held by Al-Shāfiʿī. The reasoning for requiring the ruler's judgment is that improvidence (tabdhīr) is variable, subject to differing interpretations, and necessitates independent legal reasoning (Ijtihad). Consequently, if the cause requires Ijtihad, it cannot be established except by the ruler's decree, similar to the commencement of the period of inability (ʿUnnah). Furthermore, since restriction is a matter of legal dispute, it requires the ruler's judgment, just as the restriction upon a bankrupt person (Mufllis) does. This contrasts with insanity (Junūn), which does not require Ijtihad and is not disputed.