What is the recompense for one who mocks Allah and His Messenger? And is the one who curses the Messenger to be killed if the ولي الأمر (ruler/guardian) refuses it? And what is the authenticity and interpretation of the hadith: "Indeed, his blood is now valid to be shed"?

This hadith indicates the legitimacy of killing one who insults the Prophet (peace be upon him), which is the view of many scholars, as they ruled him to be an apostate. The execution of the killing is to be carried out only by the ruler or his deputy, to prevent chaos. Scholars have agreed on the disbelief of one who insults the Prophet (peace be upon him) and the obligation to kill him. Killing is not waived by repentance if the insult was a clear slander. Scholars differed on the ruling regarding one who insults the Prophet (peace be upon him) from among the people of covenant, dhimma, and Muslims. Some of them hold the view that he should be killed unless he embraces Islam, while others believe he should be asked to repent. As for one who mocks Allah and His Messenger (peace be upon him), he is a disbeliever and deserves to be killed, based on the words of Allah Almighty: "And if you ask them, they will surely say, 'We were only jesting and playing.' Say, 'Is it in Allah and His verses and His Messenger that you were mocking?' Make no excuse; you have disbelieved after your belief." These punishments and discretionary penalties must be carried out by the ruler or his deputy.