The Book of the Adhan (The Call to Prayer)
7/9. Chapter:
Two Mu'adhdhins In One Masjid
Sunan an-Nasai
أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِنَّ بِلاَلاً يُؤَذِّنُ بِلَيْلٍ فَكُلُوا وَاشْرَبُوا حَتَّى يُنَادِيَ ابْنُ أُمِّ مَكْتُومٍ " .
It was narrated from Ibn 'Umar that the Messenger of Allah (S.A.W) said: "Bilal calls the Adhan during the night, so eat and drink until Ibn Umm Maktum calls (the Adhan)"
Reference : Sunan an-Nasa'i 637In-book reference : Book 7, Hadith 12English translation : Vol. 1, Book 7, Hadith 638