It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them) that he said: The Messenger of Allah (peace and blessings be upon him) said: "When any of the Jews greets you with Salam, he says: «السام علیک» (death be upon you), so you should also reply with «وعلیک» (death be upon you)."
Hadith Referenceالادب المفرد / كتاب أهل الكتاب / 1106
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه البخاري ، كتاب الاستئذان : 6257 و مسلم : 2164 و أبوداؤد : 5206 و الترمذي : 1603 و النسائي فى الكبرىٰ : 10138»
It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both), he said: Give a reply of salam to every Jew, Christian, and Magian, because Allah the Exalted has said: "When you are greeted with a greeting, respond with one better than it or return it in like manner." [سورہ النساء: 86]
Hadith Referenceالادب المفرد / كتاب أهل الكتاب / 1107
Hadith Gradingالألبانی:حسن
Hadith Takhrij«حسن : أخرجه ابن أبى شيبة : 25765 و ابن أبى الدنيا فى الصمت : 307 و ابن أبى حاتم فى تفسيره : 5729 و أبويعلي : 1527 - أنظر الصحيحة : 329/2»