General Behavior (Kitab Al-Adab)

Dawud :: Book 41 : Hadith 5191

Narrated Ali ibn AbuTalib:

AbuDawud said: Al-Hasan ibn Ali traced this tradition back to the Prophet (peace_be_upon_him): When people are passing by, it is enough if one of them gives a salutation on their behalf, and that it is enough for those who are sitting if one of them replies.