Chapter 40: The Book of Greetings
' A' isha reported that some Jews came to Allah' s Apostle (ﷺ) and they said: Abu' l-Qasim (the Kunya of the Holy Prophet), as-Sam-u-' Alaikum, whereupon he (the Holy Prophet) said: Wa 'Alaikum. A' isha reported: In response to these words of theirs, I said: But let there be death upon you and disgrace also, whereupon Allah' s Messenger (ﷺ) said: 'A' isha, do not use harsh words. She said: Did you hear what they said? Thereupon he (the Holy Prophet) said: Did I not respond to them when they said that; I said to them: Wa 'Alaikum (let it be upon you).
Sahih Muslim 2165c