Narrated 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).'"

Narrated `Abdullah bin Mulaika: `Aisha said that the Jews came to the Prophet and said, "As-Samu 'Alaikum" (death be on you). `Aisha said (to them), "(Death) be on you, and may Allah curse you and shower His wrath upon you!" The Prophet said, "Be calm, O `Aisha ! You should be kind and lenient, and beware of harshness and Fuhsh (i.e. bad words)." She said (to the Prophet), "Haven't you heard what they (Jews) have said?" He said, "Haven't you heard what I have said (to them)? I said the same to them, and my invocation against them will be accepted while theirs against me will be rejected (by Allah). "

Narrated `Abdullah bin `Umar: Allah's Apostle said, "When the Jews greet you, they usually say, 'As-Samu 'alaikum (Death be on you),' so you should say (in reply to them), 'Wa'alaikum (And on you).

Narrated Anas bin Malik: the Prophet said, "If the people of the Scripture greet you, then you should say (in reply), 'Wa'alaikum (And on you).' "

Narrated Anas bin Malik: A Jew passed by Allah's Apostle and said, "As-Samu 'Alaika." Allah's Apostle said in reply, "We 'Alaika." Allah's Apostle then said to his companions, "Do you know what he (the Jew) has said? He said, 'As-Samu 'Alaika.'" They said, "O Allah's Apostle! Shall we kill him?" The Prophet, said, "No. When the people of the Book greet you, say: 'Wa 'Alaikum.'"