[Machine] The Messenger of Allah ﷺ had only one muezzin who would call the adhan for him. When the Messenger of Allah ﷺ would sit on the pulpit on Fridays, he would give the call to prayer at the entrance of the mosque. Then, when he descended, he would establish the prayer. This was the case with Abu Bakr, and then with Umar, until when Uthman came, the number of people increased. So he ordered the first call to be made in the market on his own property, which is known as al-Zawra. The adhan would be called there for him. Then when Uthman sat on the pulpit, his first muezzin would give the call to prayer. And then, when he descended, he would establish the prayer.  

«مَا كَانَ لِرَسُولِ اللهِ ﷺ إِلَّا مُؤَذِّنٌ وَاحِدٌ لَمْ يَكُنْ يُؤَذِّنُ لَهُ غَيْرُهُ فَكَانُ إِذَا جَلَسَ رَسُولُ اللهِ ﷺ عَلَى الْمِنْبَرِ يَوْمَ الْجُمُعَةِ أَذَّنَ عَلَى بَابِ الْمَسْجِدِ فَإِذَا نَزَلَ أَقَامَ الصَّلَاةَ ثُمَّ كَانَ أَبُو بَكْرٍ ؓ كَذَلِكَ ثُمَّ كَانَ عُمَرُ ؓ كَذَلِكَ حَتَّى إِذَا كَانَ عُثْمَانُ كَثُرَ النَّاسُ فَأَمَرَ بِالنِّدَاءِ الْأَوَّلِ بِالسُّوقِ عَلَى دَارٍ لَهُ يُقَالُ لَهَا الزَّوْرَاءُ فَكَانَ يُؤَذَّنُ لَهُ عَلَيْهَا فَإِذَا جَلَسَ عُثْمَانُ ؓ عَلَى الْمِنْبَرِ أَذَّنَ مُؤَذِّنُهُ الْأَوَّلُ فَإِذَا نَزَلَ أَقَامَ الصَّلَاةَ»