It was narrated that As-Sa'ib bin Yazid said:

"Bilal used to call the adhan when the Messenger of Allah ﷺ sat on the minbar on Friday, and when he came down he would say the Iqamah. It continued like that during the time of Abu Bakr and 'Umar, may Allah (Subhanahu-wa-Taala) be pleased with them."

أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا الْمُعْتَمِرُ، عَنْ أَبِيهِ، عَنِ الزُّهْرِيِّ، عَنِ السَّائِبِ بْنِ يَزِيدَ، قَالَ كَانَ بِلاَلٌ يُؤَذِّنُ إِذَا جَلَسَ رَسُولُ اللَّهِ ﷺ عَلَى الْمِنْبَرِ يَوْمَ الْجُمُعَةِ فَإِذَا نَزَلَ أَقَامَ ثُمَّ كَانَ كَذَلِكَ فِي زَمَنِ أَبِي بَكْرٍ وَعُمَرَ رضى الله عنهما .