حِصْنُ الْمُسْلِمِ
Hisn al-Muslim 227
Fortress of the Muslim (Hisn al-Muslim)
Returning a greeting to a disbeliever
إذَا سَلَّمَ عَلَيْكُمْ أَهْلُ الْكِتَابِ فَقُولُوا: وَعَلَيْكُمْ
If one of the People of the Scripture (i.e. Christians and Jews) greets you, saying As-Salāmu `alaykum, then say (to him): Wa `alaykum. If one of the People of the Scripture (i.e. Christians and Jews) greets you saying As-Salaamu `alaykum, then say (to him): And upon you . Reference: Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 11/42, Muslim 4/1705.
Hisn al-Muslim, 227