(4) باب النَّهْىِ عَنِ ابْتِدَاءِ، أَهْلِ الْكِتَابِ بِالسَّلاَمِ وَكَيْفَ يَرُدُّ عَلَيْهِمْ
Anas b. Malik reported Allah's Messenger (ﷺ) as saying:
When the People of the Book offer you salutations, you should say: The same to you. (RU)
Reference (RU): Sahih Muslim 2163 a (RU)
In-book reference (RU): Book 39, Hadith 7 (RU)
USC-MSA web (English) reference(deprecated numbering scheme): Book 26, Hadith 5380 (RU)