Sunan an-Nasa'i 3
سنن النسائي#3SahihIt was narrated that Abu Musa said:"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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 1:3