Al-Adab Al-Mufrad, Hadith 1039 ⓘ
'Abdullah said, "Peace is one of the Names of Allah which Allah has placed on the earth. Extend it among you. When a man greets people and they answer him, then he has a higher degree than them because he reminds them of peace. If no one answers him, he will be answered by one who is better and more excellent.'"
حَدَّثَنَا عُمَرُ بْنُ حَفْصٍ، قَالَ: حَدَّثَنَا أَبِي، قَالَ: حَدَّثَنَا الأَعْمَشُ، قَالَ: حَدَّثَنَا زَيْدُ بْنُ وَهْبٍ، عَنْ عَبْدِ اللهِ قَالَ: إِنَّ السَّلاَمَ اسْمٌ مِنْ أَسْمَاءِ اللهِ، وَضَعَهُ اللَّهُ فِي الأَرْضِ، فَأَفْشُوهُ بَيْنَكُمْ، إِنَّ الرَّجُلَ إِذَا سَلَّمَ عَلَى الْقَوْمِ فَرَدُّوا عَلَيْهِ كَانَتْ لَهُ عَلَيْهِمْ فَضْلُ دَرَجَةٍ، لأَنَّهُ ذَكَّرَهُمُ السَّلاَمَ، وَإِنْ لَمْ يُرَدَّ عَلَيْهِ رَدَّ عَلَيْهِ مَنْ هُوَ خَيْرٌ مِنْهُ وَأَطْيَبُ.
also referenced under: Book 42, Hadith 76 (In-Book) & Book 42, Hadith 1039 (English)