Jami` at-Tirmidhi 2703
جامع الترمذي#2703SahihNarrated Al-Hasan:from Abu Hurairah that the Prophet (ﷺ) said: "The rider gives the Salam to the walking person, and the walking person to the sitting person and the few to the many." Ibn Al-Muthanna added in his narration: "And the young one gives the Salam to the elder
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 42:16