Call to Prayers (Adhaan) 
Bukhari :: Book 1 :: Volume 11 :: Hadith 662
Narrated Anas:
The Prophet said, "Listen and obey (your chief) even if an Ethiopian whose head is like a raisin were made your chief."
Call to Prayers (Adhaan)
Bukhari :: Book 1 :: Volume 11 :: Hadith 662
Narrated Anas:
The Prophet said, "Listen and obey (your chief) even if an Ethiopian whose head is like a raisin were made your chief."