From Sahih Muslim (Hadith 5656):
A'isha reported that a group of Jews came to Allah's Messenger (ﷺ) and sought his audience and said:As-Sam-u-'Alaikum. A'isha said in response: As-Sam-u-'Alaikum (death be upon you) and curse also, whereupon Allah's Messenger (ﷺ) said: 'A'isha, verily Allah loves kindness in every matter. She said: Did you bear what they said? Thereupon he said: Did you not hear that I said (to them): Wa 'Alaikum
Reference: Muslim 5656