It was narrated that 'Uthman bin Abul-As said: "The last instruction that the Messenger of Allah gave to me was that I should not appoint a Mu'adh-dhin who took payment for the Adhan." (sahih)
SahihSahihSahihBook 3 · Hadith 9
سنن ابن ماجه
It was narrated that 'Uthman bin Abul-As said: "The last instruction that the Messenger of Allah gave to me was that I should not appoint a Mu'adh-dhin who took payment for the Adhan." (sahih)