أَخْبَرَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا حَفْصٌ، عَنْ عُبَيْدِ اللَّهِ، عَنِ الْقَاسِمِ، عَنْ عَائِشَةَ، قَالَتْ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ إِذَا أَذَّنَ بِلاَلٌ فَكُلُوا وَاشْرَبُوا حَتَّى يُؤَذِّنَ ابْنُ أُمِّ مَكْتُومٍ ‏"‏ ‏.‏ قَالَتْ وَلَمْ يَكُنْ بَيْنَهُمَا إِلاَّ أَنْ يَنْزِلَ هَذَا وَيَصْعَدَ هَذَا ‏.‏

It was narrated that 'Aishah said: "The Messenger of Allah (PBUH) said: 'Bilal calls the Adhan during the night, so eat and drink until Ibn Umm Maktum calls the Adhan." She said: "And there was no more between then than the time it takes for one to come down and the other to go up." Translation Not Available

Book Ref: Sunan An Nisai Book 7 Hadith 646
Web Ref:  Sunan An Nisai Vol 1 Book 7 Hadith 640