Sunan an-Nasa'i 640
سنن النسائي#640Sahihأَخْبَرَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، عَنْ هُشَيْمٍ، قَالَ أَنْبَأَنَا مَنْصُورٌ، عَنْ خُبَيْبِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ عَمَّتِهِ، أُنَيْسَةَ قَالَتْ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا أَذَّنَ ابْنُ أُمِّ مَكْتُومٍ فَكُلُوا وَاشْرَبُوا وَإِذَا أَذَّنَ بِلاَلٌ فَلاَ تَأْكُلُوا وَلاَ تَشْرَبُوا " .
It was narrated from Khubaib bin 'Abdur-Rahman that his paternal aunt Unaisah said:"The Messenger of Allah (S.A.W) said: 'When Ibn Umm Maktum calls the Adhan, eat and drink, and when Bilal calls the Adhan, do not eat nor drink
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 7:15