Sahih Muslim 5646
صحيح مسلم#5646SahihAbu Huraira reported Allah's Messenger (ﷺ) as saying:The rider should first greet the pedestrian, and the pedestrian the one who is seated and a small group should greet a larger group (with as-Salam-u-'Alaikum)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 39:1