When the Muslims arrived at Al-Madîna, they used to assemble for As-Salat (the prayer), and used to guess the time for it. During those days, the practice of Adhân for the (prayers) had not been introduced yet. Once they discussed this problem regarding the call for (prayer). Some people suggested the use of a bell like the Christians, others proposed a trumpet like the horn used by the Jews, but 'Umar was the first to suggest that a man should call (the people) for As-Salât (the prayer); so Allâh's Messenger (ﷺ) ordered Bilâl to get up and pronounce the Adhân for As-Salât (the prayer). [1:578-0.B.]