Prayer (Kitab Al-Salat) 
Dawud :: Book 2 : Hadith 534
Narrated Bilal:
The Apostle of Allah (peace_be_upon_him) said to Bilal: Do not call adhan until the dawn appears clearly to you in this way, stretching his hand in latitude.
Prayer (Kitab Al-Salat)
Dawud :: Book 2 : Hadith 534
Narrated Bilal:
The Apostle of Allah (peace_be_upon_him) said to Bilal: Do not call adhan until the dawn appears clearly to you in this way, stretching his hand in latitude.