Bukhari 2656

Narrated `Abdullah bin `Umar:The Prophet (ﷺ) said, "Bilal pronounces the Adhan when it is still night (before dawn), so eat and drink till the next Adhan is pronounced (or till you hear Ibn Um Maktum's Adhan)." Ibn Um Maktum was a blind man who would not pronounce the Adhan till he was told that it was dawn