Sahih Bukhari
Sahih Bukhari Volume 009, Book 084, Hadith Number 062.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 84. Dealing with Apostates
Narrated By Ibn 'Umar : Allah's Apostle said, "When the Jews greet anyone of you they say: 'Sam'Alaika (death be upon you); so you should say; 'Wa 'Alaika (and upon you).'"