In the lifetime of the Prophet, Abu Bakr and ʿUmar, the Adhan for the Jumua prayer used to be pronounced when the Imam sat on the pulpit. But during the Caliphate of ʿUthman when the Muslims increased in number, a third Adhan at Az-Zaura' was added. Abu ʿAbdullah said, "Az-Zaura' is a place in the market of Medina."
كَانَ النِّدَاءُ يَوْمَ الْجُمُعَةِ أَوَّلُهُ إِذَا جَلَسَ الإِمَامُ عَلَى الْمِنْبَرِ عَلَى عَهْدِ النَّبِيِّ ﷺ وَأَبِي بَكْرٍ وَعُمَرَ ؓ فَلَمَّا كَانَ عُثْمَانُ ؓ وَكَثُرَ النَّاسُ زَادَ النِّدَاءَ الثَّالِثَ عَلَى الزَّوْرَاءِ