Sunan an-Nasa'i #3 · The Book of Purification

Sunan an-Nasa'iIt was narrated that Abu Musa said
Sunan an-Nasa'i · Book 1 · The Book of Purification
Sunan an-Nasa'i · كتاب 1 · كتاب الطهارة
"I came to the Messenger of Allah (ﷺ) when he was using the Siwak, and the end of the Siwak was on his toungue, and he was saying, " 'a,'a " ("‏ عَأْعَأْ ‏")".
أَخْبَرَنَا أَحْمَدُ بْنُ عَبْدَةَ، قَالَ حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، قَالَ أَخْبَرَنَا غَيْلاَنُ بْنُ جَرِيرٍ، عَنْ أَبِي بُرْدَةَ، عَنْ أَبِي مُوسَى، قَالَ دَخَلْتُ عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم وَهُوَ يَسْتَنُّ وَطَرَفُ السِّوَاكِ عَلَى لِسَانِهِ وَهُوَ يَقُولُ ‏
"‏ عَأْعَأْ ‏"‏ ‏.‏
Reference : Sunan an-Nasa'i 3In-book reference : Book 1, Hadith 3