It is narrated from Hazrat Anas (may Allah be pleased with him) that once a man from the People of the Book came to the Prophet’s court and, greeting the Prophet (peace be upon him), said, "As-Saam Alaik" (death be upon you). The Prophet (peace be upon him) replied, "Wa Alaik" (and upon you). Then the Prophet (peace be upon him) said to the companions (may Allah be pleased with them), "Do you know what he said? He said, 'As-Saam Alaik.'" Upon hearing this, the companions (may Allah be pleased with them) said, "O Messenger of Allah (peace be upon him)! Should we not strike off his neck?" The Prophet (peace be upon him) said, "No, but when the People of the Book greet you, you should only say, 'Wa Alaikum.'"