Sayyiduna Sa’ib bin Yazid رضي الله عنه narrates that during the time of the Messenger of Allah صلى الله عليه وآله وسلم, Sayyiduna Abu Bakr and Sayyiduna Umar رضي الله عنهما, there used to be only one mu’adhdhin for Jumu’ah and all other prayers, until Sayyiduna Uthman رضي الله عنه became the caliph. Sayyiduna Sa’ib bin Yazid رضي الله عنه says that on the day of Jumu’ah, when the Messenger صلى الله عليه وآله وسلم would sit on the pulpit, Sayyiduna Bilal رضي الله عنه would call the adhan, and when the Prophet صلى الله عليه وآله وسلم would descend, Sayyiduna Bilal رضي الله عنه would call the iqamah.