It is noteworthy that Sheikh Abu-Ishaq al-Huwayni says that one who insults Muhammad must be killed, but not one who insults Allah. For all the indignant rejection by Muslims of the old term "Mohammedan," Islam is actually quite Muhammad-centric. "Egyptian Shaykh: 'We still kill him, even if he repents!,'" from Translating Jihad, July 13:
The above clip was taken from an interview given by Shaykh Abu-Ishaq al-Huwayni on the Egyptian satellite television station al-Hikma on 7 July 2011. Al-Huwayni here explains that whoever insults Muhammad, even if he later repents, must be killed.
Later in the interview, al-Huwayni went on to contrast this with the case of one who insults Allah. He said that insulting Allah of course makes one an infidel, which is agreed to by all Islamic scholars, yet the one who insults Allah is not killed--he is merely called to repentance. This is because even if the whole world insults Allah, it does not matter to him--it does not hurt him. [...]
Subtitled video above, transcript below:Whoever insults the Prophet (PBUH), if he later comes and apologizes, and kisses the shoes (of the ruler), and says, “I want all Muslims, every one, to return and strike me with the soles of their feet”—does the ruler have the right to accept this?
I bring up this question, as it was asked of me. The answer is that it is not permissible for anyone to accept this. Then what do we do with him? We kill him! But he told you that he repented. We still kill him, even if he repents!