Al-Taher al-Hashemi stressed, though, that call should have been made much earlier, before the spread of Takfiri terrorism in the region.
He said scholars from Iran, Lebanon, Iraq, Egypt and Syria should take part in the gathering.
Al-Hashemi further underlined that Takfiri terrorists are not Sunnis because Shunni Muslims are moderate and do not have deviated and radical ideas.
All Muslims must unite to eradicate the deviated Takfiri ideology, he went on to say.
The Middle East has been facing the growing threat of Takfiri terrorism in recent years, with terrorist groups like ISIL (ISIS) spreading their criminal activities to countries like Syria, Iraq and Libya.
These extremist have been committing heinous atrocities against Muslims and others in the areas they operate.