(457) بَابُ يُسَلِّمُ الصَّغِيرُ عَلَى الْكَبِيرِ
Abu Hurayra reported that the Messenger of Allah, may Allah blesshim and grant him peace, said, "The young person greets the old person,the person walking greets the person sitting down, and the small groupgreets the large group."
Reference: Al-Adab Al-Mufrad 1001
In-book reference: Book 42, Hadith 37
English translation: Book 42, Hadith 1001