'Abdullah ibn 'Umar said that the Messenger of Allah, may Allah
bless him and grant him peace, said, "When one of the Jews greets you and
says, 'Poison be upon you (as-samu 'alaykum),' say, 'And on you.'"
حَدَّثَنَا عَمْرُو بْنُ عَاصِمٍ، قَالَ: حَدَّثَنَا هَمَّامٌ، قَالَ: حَدَّثَنَا قَتَادَةُ، عَنْ أَنَسٍ قَالَ: مَرَّ يَهُودِيٌّ عَلَى النَّبِيِّ صلى الله عليه وسلم فَقَالَ: السَّامُ عَلَيْكُمْ، فَرَدَّ أَصْحَابُهُ السَّلاَمَ، فَقَالَ: قَالَ: السَّامُ عَلَيْكُمْ، فَأُخِذَ الْيَهُودِيُّ فَاعْتَرَفَ، قَالَ: رُدُّوا عَلَيْهِ مَا قَالَ.
Anas said, "A Jew passed by the Prophet, may Allah bless him and
grant him peace, saying, 'Peace be upon you.' His Companions returned the
salam.' The Prophet said, 'The Jew said, 'Poison (sam) be upon you.'
He caught hold of the Jew who admitted it.' The Prophet said, 'Answer him
with what he said.'"
Ibn 'Abbas said, "Return the greeting to whomever it is, Jew,
Christian, or Magian. That is because Allah says, 'When you are greeted
with a greeting, greet with one better than it or return it.' (4:86)"
