Ibn 'Umar (Allah be pleased with both of them) reported that the Messenger of Allah ( صلی اللہ علیہ وسلم ) had two Mu'adhdhins, Bilal and son of Umm Maktum, the blind. The Messenger of Allah ( صلی اللہ علیہ وسلم ) said:
Bilal announces Adhan at (the fag end of the) night (i. e. Sahri), so eat and drink till the son of Umm Maktum announces Adhan. And he (the narrator) said: And the (difference of time) between their (Adhans) was not more than this that one climbed down (from the minaret) and the other climbed up (to announce Adhan).