Sahih Bukhari
Accepting Information Given by a Truthful Person
Volume: 009 / Book Number: 091 / Hadith Number: 354
Narrated 'Abdullah bin 'Umar:
The Prophet said, "Bilal pronounces the Adhan at night so that you may eat and drink till Ibn Um Maktum pronounces the Adhan (for the Fajr prayer)."