(4) باب تَسْلِيمِ الْقَلِيلِ عَلَى الْكَثِيرِ
Narrated Abu Huraira:
The Prophet (ﷺ) said, "The young should greet the old, the passer by should greet the sitting one, and the small group of persons should greet the large group of persons. "
Reference: Sahih al-Bukhari 6231
In-book reference: Book 79, Hadith 5
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 74, Hadith 250