I stand corrected. Jazakallahu khairan.
What he did was not an insult. However, it was kufr as it entailed rejection of the status of the Prophet صلى الله عليه وسلم.
Dr. Mohammed Morsi.
Hamza Kashgari didn't think he was insulting the Prophet (sallallaahu alayhi wa sallam) either. So you're just arguing for the sake of arguing?
According to ibn Khaldun, the following four works are the foundations of Arabic Literature (al-Adab al-Arabi): (1) Al-Bayan wa 'l-Tabyin, by al-Jahiz (2) Al-Kamil, by al-Mubarrid (3) Al-Amali,...