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

سَمِعْتُ أَنَسَ بْنَ مَالِكٍ يَقُولُ مَرَّ يَهُودِيٌّ بِرَسُولِ اللَّهِ ﷺ فَقَالَ السَّامُ عَلَيْكَ فَقَالَ رَسُولُ اللَّهِ ﷺ وَعَلَيْكَ فَقَالَ رَسُولُ اللَّهِ ﷺ أَتَدْرُونَ مَا يَقُولُ قَالَ السَّامُ عَلَيْكَ قَالُوا يَا رَسُولَ اللَّهِ أَلاَ نَقْتُلُهُ قَالَ لاَ إِذَا سَلَّمَ عَلَيْكُمْ أَهْلُ الْكِتَابِ فَقُولُوا وَعَلَيْكُمْ  

A Jew came to the Prophet of Allah and his Companions and said: “As-Samu Alaikum (Death be upon you).” So the people replied to him. The Prophet of Allah said: “Do you know what this person said?” They said: “Allah and His Messenger know better – he said the Salam – O Allah’s Prophet.” He said: “No, rather he said like this and that. Bring him back for e=me.” So they brought him back and he said: “Did you say As-Samu Alaikum? He said: “Yes.” So with that Allah’s Prophet said: “When one of the People of the Book gives you the Salam, then say: “Alaika Ma Qulta (Whatever you said to you too).” He said: ‘And when they come to you, they greet you with a greeting wherewith Allah greets you not.’ (Using translation from Tirmidhī 3301)   

أَنَّ يَهُودِيًّا مَرَّ عَلَى رَسُولِ اللهِ ﷺ وَأَصْحَابِهِ فَقَالَ السَّامُ عَلَيْكُمْ فَقَالَ نَبِيُّ اللهِ ﷺ أَتَدْرُونَ مَا قَالَ هَذَا؟ قَالُوا سَلَّمَ يَا رَسُولَ اللهِ قَالَ لَا وَلَكِنَّهُ قَالَ كَذَا وَكَذَا ثُمَّ قَالَ رُدُّوهُ عَلَيَّ فَرَدُّوهُ عَلَيْهِ فَقَالَ قُلْتَ السَّامُ عَلَيْكُمْ قَالَ نَعَمْ فَقَالَ نَبِيُّ اللهِ ﷺ عِنْدَ ذَلِكَ إِذَا سَلَّمَ عَلَيْكُمْ أَحَدٌ مِنْ أَهْلِ الْكِتَابِ فَقُولُوا وَعَلَيْكَ أَيْ وَعَلَيْكَ مَا قُلْتَ  

[Machine] I heard Anas say that a man from the people of the Book came and greeted the Prophet ﷺ . He said "As-Salamu Alaykum" (peace be upon you), and Umar said, "O Messenger of Allah, should I not strike his neck?" The Prophet ﷺ said, "No, if they greet you with peace, then say 'wa 'alaykum" (and peace be upon you too).  

سَمِعْتُ أَنَسًا يَقُولُ جَاءَ رَجُلٌ مِنْ أَهْلِ الْكِتَابِ فَسَلَّمَ عَلَى النَّبِيِّ ﷺ فَقَالَ السَّامُ عَلَيْكُمْ فَقَالَ عُمَرُ يَا رَسُولَ اللهِ أَلَا أَضْرِبُ عُنُقَهُ؟ قَالَ لَا إِذَا سَلَّمُوا عَلَيْكُمْ فَقُولُوا وَعَلَيْكُمْ  

[Machine] A Jew came to the Prophet ﷺ while he was with his companions, and he said, "Peace be upon you." The people replied to him and said, "And upon you be peace, O Messenger of Allah." The Prophet ﷺ then asked them, "Do you know what he said?" They said, "Yes, he said, 'Peace be upon you.'" The Prophet ﷺ said, "Respond to him by saying, 'Upon you be the same.'" So they responded to the man and said, "Upon you be the same." Then the Prophet ﷺ asked the man, "Did you say such and such?" He said, "Yes." The Prophet ﷺ then said, "When anyone from the People of the Book greets you with peace, say, 'And upon you be peace,' meaning upon you be what you have said."  

أَنَّ يَهُودِيًّا أَتَى النَّبِيَّ ﷺ وَهُوَ مَعَ أَصْحَابِهِ فَقَالَ السَّامُ عَلَيْكُمْ فَرَدَّ عَلَيْهِ الْقَوْمُ فَقَالَ نَبِيُّ اللهِ ﷺ أَتَدْرُونَ مَا قَالَ؟ قَالُوا نَعَمْ قَالَ السَّامُ عَلَيْكُمْ قَالَ رُدُّوا عَلَيَّ الرَّجُلَ فَرَدُّوهُ فَقَالَ نَبِيُّ اللهِ ﷺ قُلْتَ كَذَا وَكَذَا؟ قَالَ نَعَمْ فَقَالَ نَبِيُّ اللهِ ﷺ إِذَا سَلَّمَ عَلَيْكُمْ أَحَدٌ مِنْ أَهْلِ الْكِتَابِ فَقُولُوا عَلَيْكَ أَيْ عَلَيْكَ مَا قُلْتَ  

[Machine] While the Prophet of Allah ﷺ was sitting with his companions, a Jew passed by them and greeted them. The Prophet ﷺ said, "Return his greeting." They asked, "How should we do that?" The Prophet ﷺ said, "You should reply 'And upon you' when he greets you, just as you would say 'Peace be upon you' when he greets you."  

بَيْنَمَا نَبِيُّ اللهِ ﷺ جَالِسٌ فِي أَصْحَابِهِ إِذْ مَرَّ بِهِمْ يَهُودِيٌّ فَسَلَّمَ عَلَيْهِمْ فَقَالَ النَّبِيُّ ﷺ رُدُّوهُ فَقَالَ كَيْفَ؟ قُلْتَ قَالَ قُلْتُ سَامٌ عَلَيْكُمْ؟ فَقَالَ رَسُولُ اللهِ ﷺ إِذَا سَلَّمَ عَلَيْكُمْ أَحَدٌ مِنْ أَهْلِ الْكِتَابِ فَقُولُوا وَعَلَيْكَ أَيْ مَا قُلْتَ  

[Machine] "A Jew greeted the Messenger of Allah ﷺ and said 'As-Salamu Alaikum' (peace be upon you). The Prophet ﷺ responded by saying 'Return the greeting to me'. The Jew asked, 'Did you say As-Salamu Alaikum (peace be upon you)?' The Prophet ﷺ replied, 'Yes'. Then the Messenger of Allah ﷺ said, 'When anyone from the People of the Book greets you with Salam, say 'Wa Alaikum' (and upon you).'  

أَنَّ يَهُودِيًّا سَلَّمَ عَلَى رَسُولِ اللهِ ﷺ فَقَالَ السَّامُ عَلَيْكَ قَالَ رُدُّوهُ عَلَيَّ قَالَ أَقُلْتَ السَّامُ عَلَيْكَ؟ قَالَ نَعَمْ فَقَالَ رَسُولُ اللهِ ﷺ إِذَا سَلَّمَ عَلَيْكُمْ أَحَدٌ مِنْ أَهْلِ الْكِتَابِ فَقُولُوا وَعَلَيْكَ  

[Machine] "About the Prophet ﷺ, when a Jew greets you with the word 'As-salamu alaykum', he is only saying 'death be upon you,' so respond with 'wa alaykum' (and upon you). And he also mentioned once, when the Jews greet you, say 'wa alaykum' (and upon you), as they are saying 'death be upon you.'"  

عَنِ النَّبِيِّ ﷺ إِذَا سَلَّمَ عَلَيْكَ الْيَهُودِيُّ فَإِنَّمَا يَقُولُ السَّامُ عَلَيْكَ فَقُلْ وَعَلَيْكَ وَقَالَ مَرَّةً إِذَا سَلَّمَ عَلَيْكُمُ الْيَهُودُ فَقُولُوا وَعَلَيْكُمْ فَإِنَّهُمْ يَقُولُونَ السَّامُ عَلَيْكُمْ  

[Machine] "A Jew greeted the Prophet ﷺ and his companions, saying, 'As-salamu 'alaykum' (peace be upon you). The Prophet ﷺ asked, 'Do you know what he said?' They replied, 'Yes, he greeted us by saying 'as-salamu 'alaykum.' The Prophet ﷺ said, 'No, he actually said 'as-samu 'alaykum' (death be upon you), meaning that you should abandon your religion. So when a person from the People of the Book greets you, respond by saying 'wa 'alayk' (and upon you).'"  

أَنَّ يَهُودِيًّا سَلَّمَ عَلَى النَّبِيِّ ﷺ وَأَصْحَابِهِ فقَالَ السَّامُ عَلَيْكُمْ فقَالَ النَّبِيُّ ﷺ «أَتَدْرُونَ مَا قَالَ؟ » قَالُوا نَعَمْ سَلَّمَ عَلَيْنَا قَالَ «لَا إِنَّمَا قَالَ السَّامُ عَلَيْكُمْ أَيْ تُسَامُونَ دِينَكُمْ فَإِذَا سَلَّمَ عَلَيْكُمْ رَجُلٌ مِنْ أَهْلِ الْكِتَابِ فَقُولُوا وَعَلَيْكَ»  

"أتدرون ما قال؟ قالوا: سلَّم علينا، قال: لا، إنما قال: السَّأمُ عليكم - أى تسأمون دينكم - فإذا سلم عليكم رجل من أهل الكتاب فقولوا: وعليك".