'Abdur-Rahrnan bin Sa'd bin 'Ammar bin Sa'd, the Mu'adhdhin of the Prophet P.B.U.H, said: "My father told me, narrating from his father, from his grandfather, that during the time of the Messenger of Allah P.B.U.H, he used to call the Adhan on Fridays when the shadow was like a sandal strap." (Da'if)