The Book of Prayers (Kitab Al-Salat) 
Muslim :: Book 4 : Hadith 741
Ibn Umar reported: The Messenger of Allah (may peace be upon him) had two Mu'adhdhins, Bilal and 'Abdullah b. Umm Maktum, who (latter) was blind.
The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 741
Ibn Umar reported: The Messenger of Allah (may peace be upon him) had two Mu'adhdhins, Bilal and 'Abdullah b. Umm Maktum, who (latter) was blind.