(475) بَابُ مَنْ لَمْ يَرُدَّ السَّلامَ
Al-Hasan said, "Greeting is an act of obedience while the answeris a duty." (RU)
Reference (RU): Al-Adab Al-Mufrad 1040 (RU)
In-book reference (RU): Book 42, Hadith 77 (RU)
English translation (RU): Book 42, Hadith 1040 (RU)