Narrated from Sayyiduna Anas (may Allah be pleased with him) that a Jew came to the Noble Prophet (peace and blessings be upon him) while he was sitting with his companions, and he said: "As-Saam Alaikum (death be upon you)." The people replied to him, but the Messenger of Allah (peace and blessings be upon him) said to him: "Did you say such and such?" He said: "Yes." Then the Prophet (peace and blessings be upon him) said: "When any of the People of the Book greet you, then you should only say 'Alaika (upon you).' That is, whatever you said, the same be upon you."