How the Adhan was started

 190. Abdullah bin ´Umar said: When the Muslims came to Al-Madinah, they used to gather and wait for the prayer time, but there was no one to summon them. One day the discussed the matter, and some of them said: ´´Use a bell like the Christians,´´ and some of them said: ´´Use horn like Jews.´´ Umar said: ´´Why do you not send a man to summon people to prayer?´´ The Messenger of Allah salla alayhi wa sallam said: ´´O Bilal, get up and call the Adhan for prayer.´´