"When any of the People of the Book greets you with Salam (peace), then say, Wa 'alaikum(and also upon you)."
Sunan Ibn Majah Book 33, Hadith 41
← Previous Hadith "Jibrail send (greetings of) Salam to you." She said: "Wa 'alahisalam wa rahmatullah (and upon him be peace and mercy of Allah)."

Sunan Ibn Majah Book 33, Hadith 40 Next Hadith → "Assam o alaika (death be upon you), O Abul-Qasim!" He said: "Wa 'alayikum (and also upon you)."

Sunan Ibn Majah Book 33, Hadith 42