Sunan Ibn Majah 3697
It was narrated that Anas bin Malik said "the Messenger of Allahﷺ said":
"When any of the People of the Book greets you with Salam (peace), then say, Wa 'alaikum(and also upon you)."
حَدَّثَنَا أَبُو بَكْرٍ، حَدَّثَنَا عَبْدَةُ بْنُ سُلَيْمَانَ، وَمُحَمَّدُ بْنُ بِشْرٍ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ قَالَ رَسُولُ اللَّهِ ـ ﷺ ـ " إِذَا سَلَّمَ عَلَيْكُمْ أَحَدٌ مِنْ أَهْلِ الْكِتَابِ فَقُولُوا وَعَلَيْكُمْ " .
Classification
Sahih (Authentic) [Darussalam]
References
Sunan Ibn Majah 3697
Sunan Ibn Majah Vol. 5, Book of Etiquette, Hadith 3697