Sunan an-Nasa'i 1323
سنن النسائي#1323SahihIt was narrated that 'Abdullah said:"The Messenger of Allah (ﷺ) used to say the salam to his right so that the whiteness of his cheek could be seen, and to his left so that the whiteness of his cheek could be seen
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
In-book reference: 13:145