(4) باب النَّهْىِ عَنِ ابْتِدَاءِ، أَهْلِ الْكِتَابِ بِالسَّلاَمِ وَكَيْفَ يَرُدُّ عَلَيْهِمْ
Ibn 'Umar reported Allah's Messenger (ﷺ) as saying:
When the Jews offer you salutations, some of them say as-Sam-u-'Alaikum (death be upon you). You should say (in response to it): Let it be upon you. (ID)
Reference (ID): Sahih Muslim 2164 a (ID)
In-book reference (ID): Book 39, Hadith 9 (ID)
USC-MSA web (English) reference(deprecated numbering scheme): Book 26, Hadith 5382 (ID)