What happened when the number of Muslims in Medina increased, according to the hadith narrated by As-Saib bin Yazid?
 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 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).