(7) باب تَسْلِيمِ الصَّغِيرِ عَلَى الْكَبِيرِ
Narrated Abu Huraira:
Allah's Messenger (ﷺ) said, "The younger person should greet the older one, and the walking person should greet the sitting one, and the small number of persons should greet the large number of persons."
Reference: Sahih al-Bukhari 6234
In-book reference: Book 79, Hadith 8
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 74, Hadith 252