Sunan an-Nasa'i 1621
سنن النسائي#1621SahihIt was narrated from Hudhaifah that:When the Prophet (ﷺ) got up to pray at night, he would brush his teeth with the siwak
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 ZaiHasan
In-book reference: 20:24