Is the hadd punishment to be carried out on one who reviled the Prophet, may Allah's peace and blessings be upon him—and refuge is sought in Allah—but whose case was not brought before the ruler?

Whoever reviles the Prophet, peace and blessings be upon him, has apostatized. The punishment for this act is to be carried out by the ruler or his deputy, not by the common people. If he repents, his repentance is accepted, and his case is not to be brought before the ruler. However, if he does not repent and openly declares his sin, then his case is to be brought before the ruler so that the punishment may be carried out upon him.