Al-Adab Al-Mufrad, Hadith 979 ⓘ
Al-Bara' reported that the Prophet, may Allah bless him and grant him peace, said, "Make the greeting common practice among you and you will be safe."
حَدَّثَنَا مُسَدَّدٌ، قَالَ: حَدَّثَنَا عَبْدُ الْوَاحِدِ، عَنْ قِنَانَ بْنِ عَبْدِ اللهِ النَّهْمِيِّ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ عَوْسَجَةَ، عَنِ الْبَرَاءِ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ: أَفْشُوا السَّلامَ تَسْلَمُوا.
also referenced under: Book 42, Hadith 15 (In-Book) & Book 42, Hadith 979 (English)