dua, after which the muezzin calls the iqāmah. This signals the start of the main two rak'at prayer of Jum'ah. In Shia Islam In Shia Islam, Salat al-Jum'ah is Wajib Takhyiri (at the time of Occultation), which means that we have an option to offer Jum'ah prayers, if its necessary conditions are fulfilled, or to offer Zuhr prayers. Hence, if Salat al-Jum'ah is offered then it is not necessary to offer Zuhr prayer. It is also recommended by Shiite Scholars to attend Jum'ah as it will become Wajib after the appearance of Imam al-Mahdi and Jesus Christ (Isa). Shiite (Imamite) attach high significance to the presence of a just ruler or his representative or Faqih and in the absence of a just ruler or his representative and a just faqih, there exists an option between performing either the Friday or the zuhr prayer, although preference lies with the performance of Friday prayer. History According to the history of Islam and the report from Abdullah bn 'Abbas narrated from the Prophet saying that: the permission to perform the Friday prayer was given by Allah before hijrah, but the people were unable to congregate and perform it. The Prophet wrote a note to Mus'ab b. Umair, who represented the Prophet in Madinah to pray two raka'at in congregation on Friday (that is, Jumu'ah). Then, after the migration of the Prophet to Medina, the Jumu'ah was held by him. For Shiites, historically, their clergy discouraged Shiites from attending Friday prayers. According to them, communal Friday prayers with a sermon were wrong and had lapsed (along with several other religious practices) until the return of their 12th Imam, Muhammad al-Mahdi. However, among others, Shiite modernist Muhammad ibn Muhammad Mahdi al-Khalisi (1890–1963) demanded that Shiites should more carefully observe Friday prayers in a step to bridge the gap with Sunnis. Later, the practice of communal Friday prayers was developed, and became standard there-afterwards, by Ruhollah Khomeini in Iran and later by Mohammad Mohammad Sadeq al-Sadr in Iraq. They justified the practice under the newly promoted Guardianship of the Islamic Jurists doctrine. When al-Sadr installed Friday prayer imams in Shia-majority areas—a practice not traditional in Iraqi Shiism and considered "revolutionary, if not heretical"—it put him at odds with the Shia religious establishment in Najaf. Under both Khomeini and al-Sadr, political sermons would be heard. Attendance rates The world's largest Muslim population can be found in Indonesia,