بُلُوغُ الْمَرَامِ
Bulugh al-Maram 183
The Book of Prayer
وَعَنْ أَبِي مَحْذُورَةَ - رضى الله عنه - { أَنَّ اَلنَّبِيَّ - صلى الله عليه وسلم -أَعْجَبَهُ صَوْتُهُ, فَعَلَّمَهُ اَلْآذَانَ } رَوَاهُ اِبْنُ خُزَيْمَةَ [1] .
Narrated Abu Mandhura (RA): The Prophet (ﷺ) liked his voice, so he taught him the Adhan (call to prayer). [Reported by Ibn Khuzaimah].
Sunnah.com reference: Book 2, Hadith 43