Sunan Abi Dawud 533

Nafi' reported :A mu'adhdhin of ‘Umar, named Masruh, called the Adhan for the morning prayer before the break of dawn; ‘Umar commanded him (to repeat). The narrator reported the tradition in a similar way. Abu Dawud said: This tradition has been transmitted by al-Darawardi from ‘Ubaid Allah on the authority of Ibn ‘Umar, saying: there was a mu'adhdhin of ‘Umar, named Mas’ud. He then narrated the rest of the tradition. This version is more correct than one