(4) باب مَا يُقَالُ إِذَا أَذَّنَ الْمُؤَذِّنُ
It was narrated that Abu Sa'eed Al-Khudri said:
"The Messenger of Allah said: 'When you hear the call (to prayer), say what the Mu'adh-dhin says.'" (ID)
Reference (ID): Sunan Ibn Majah 720 (ID)
In-book reference (ID): Book 3, Hadith 15 (ID)
English translation (ID): Vol. 1, Book 3, Hadith 720 (ID)