“when Muslim mobs around the world make liars of us all, Muhammad included?”
Except, as Robert Spencer explains:
But actually, Islam mandates death for non-Muslim subjects of the Islamic state who mention “something impermissible about Allah, the Prophet (Allah bless him and give him peace), or Islam” (‘Umdat al-Salik, o11.10), and such laws go back to passages in the Hadith and Sira in which Muhammad orders the murders of people who have insulted him, including Abu ‘Afak, who was over one hundred years old, and the poetess ‘Asma bint Marwan.
