Sunan an-Nasa'i, Book 7, Hadith 684 (In-Book) ⓘ
It was narrated that Abu Umamah bin Sahl said: "I heard Mu'awiyah say: 'I heard the Messenger of Allah, when he heard the Mu'adhdhin, repeating what he said.'"
أَخْبَرَنَا مُحَمَّدُ بْنُ قُدَامَةَ، حَدَّثَنَا جَرِيرٌ، عَنْ مِسْعَرٍ، عَنْ مُجَمِّعٍ، عَنْ أَبِي أُمَامَةَ بْنِ سَهْلٍ، قَالَ سَمِعْتُ مُعَاوِيَةَ، - رضى الله عنه - يَقُولُ سَمِعْتُ مِنْ، رَسُولِ اللَّهِ صلى الله عليه وسلم وَسَمِعَ الْمُؤَذِّنَ فَقَالَ مِثْلَ مَا قَالَ .
also referenced under: Volume 1, Book 7, Hadith 677 (DarusSalam)