The People. of the Book offer us salutations (by saying as-Salamu- 'Alaikum). How should we reciprocate them? Thereupon he said: Say: Wa 'Alaikum (and upon you too).
Sahih Muslim Book 39, Hadith 8
← Previous Hadith When the People of the Book offer you salutations, you should say: The same to you.

Sahih Muslim Book 39, Hadith 7 Next Hadith → When the Jews offer you salutations, some of them say as-Sam-u-'Alaikum (death be upon you). You should say (in response to it): Let it be upon you.

Sahih Muslim Book 39, Hadith 9