Narrated As-Saib bin Yazid:
The person who increased the number of Adhans for the Jumua prayers to three was `Uthman bin `Affan and it was when the number of the (Muslim) people of Medina had increased. In the lifetime of the Prophet (ﷺ) there was only one Mu'adh-dhin and the Adhan used to be pronounced only after the Imam had taken his seat (i.e. on the pulpit).
Reference | : Sahih al-Bukhari 913 |
In-book reference | : Book 11, Hadith 37 |
USC-MSA web (English) reference | : Vol. 2, Book 13, Hadith 36 |
(deprecated numbering scheme) |