Saaib bin Yazid reported,
On the day of Jumuah, during the time of the Prophet ﷺ, Abu Bakr, and Umar 
, the call to prayer was first made when the imam sat on the pulpit. When Uthman 
became caliph and the people had grown numerous, he added a third call from atop az-Zawra.
Azami 3344
Sahihعن السائب بن يزيد قال
كان النداء يوم الجمعة أوله إذا جلس الإمام على المنبر على عهد النبي ﷺ، وأبي بكر، وعمر رضي الله عنهما، فلما كان عثمان رضي الله عنه، وكثر الناس زاد النداء الثالث على الزوراء.
Bukhari reported it in the Book of Friday Prayer (912) from Adam, who said, our teacher Ibn Abu Dhib narrated to us, from Zuhri, from Saaib bin Yazid, and he related it. Bukhari also narrated it (916) through another route from Zuhri, adding at the end, "So the matter remained established on that basis." In a version from Abu Dawud (1089), "The Messenger of Allah ﷺ had only one muezzin, Bilal."Regarding the wording "the third call," in one version it is "the second calling," and in another version it is "the first call was added." Whoever said "the third" meant the call that Uthman added, along with the call that occurs when the imam sits on the pulpit, followed by the iqamah. Whoever said "the second calling" did not mean second in rank, but rather meant that it was an addition to the first. Whoever said "the first call" meant first in rank.As for the statement "the matter remained established on that basis," it means that none of the companions objected to his addition of the first call, and the practice continued to be followed.Regarding the phrase "at Zawra," Zawra was the name of a house that stood in the marketplace of Madinah. This is clarified in the version of Ibn Majah (1135) and Ibn Khuzayma (1837), where it states, "He added the third call at a house in the marketplace called Zawra."