Short answer
It is makruh (disliked) in the Hanafi school to start a non-Muslim greeting with as-salamu alaykum, unless there is a need. Greet them warmly with hello, good morning or similar instead. If a non-Muslim says salam to you, reply with wa alaykum (and on you), or with a full reply when the greeting is clearly sincere.
Initiating the Islamic greeting to a non-Muslim is makruh, and permitted when there is a need or a reason such as maintaining good relations. Replying is permitted, and the reply in the hadith is wa alaykum. General greetings like hello and good morning are fully permitted.
Other madhhabs
- Shafi'i
- Initiating salam with a non-Muslim is not permitted in the relied-upon view; replying with wa alaykum.
- Hanbali
- Initiating salam is not permitted; replying with wa alaykum.
Explanation
As-salamu alaykum is a prayer for peace and safety from Allah, and the Prophet ﷺ taught Muslims not to start it with Jews and Christians in his time, and to answer their greeting with wa alaykum. Some scholars connect the hadith to a situation of hostility, when some greeted him with a twisted phrase meaning death upon you. That is why the rule is softer in daily life with peaceful neighbours.
- Starting a greeting: use hello, hi, good morning, peace be with you, or a warm smile. This is fully in line with good manners.
- When they say salam to you: answer. The Quran tells us to return a greeting with a better one or at least the same. Wa alaykum is the sunnah reply; if it is clearly sincere, some scholars allow wa alaykum as-salam.
- Mixed groups: if Muslims and non-Muslims are together, say salam with the intention of greeting the Muslims.
- Letters and emails: greetings like "Peace be upon those who follow guidance" were used by the Prophet ﷺ in letters, but in normal work email a polite "Dear" or "Hello" is fine.
A non-Muslim saying salam to a Muslim friend is usually a gesture of warmth. Receive it that way and respond kindly. See Islamic phrases and their replies.
The evidence
Quran, Surah An-Nisaa 4:86
وَإِذَا حُيِّيتُم بِتَحِيَّةٍۢ فَحَيُّوا۟ بِأَحْسَنَ مِنْهَآ أَوْ رُدُّوهَآ ۗ إِنَّ ٱللَّهَ كَانَ عَلَىٰ كُلِّ شَىْءٍ حَسِيبًا ﴿٨٦﴾
And when you are greeted with a greeting, greet [in return] with one better than it or [at least] return it [in a like manner]. Indeed, Allah is ever, over all things, an Accountant.
Any greeting should be returned at least in kind.
Sahih Muslim 2167
Sahih... لا تبدءوا اليهود ولا النصارى بالسلام ...
"Do not be the first to greet the Jews and the Christians with salam."
The basis for not initiating the Islamic greeting.
Sahih al-Bukhari 6258
Sahih... إذا سلم عليكم أهل الكتاب فقولوا وعليكم ...
"When the People of the Book greet you with salam, say: and on you."
The sunnah reply to a non-Muslim's salam.
Where the ruling is recorded
- al-Durr al-Mukhtar, Kitab al-Hazr wa al-Ibahah, the discussion of salam. Initiating salam with a non-Muslim is disliked except for a need, and replying is allowed.
- al-Adhkar (Nawawi), Kitab al-Salam, the chapter on greeting non-Muslims. The Shafi'i view against initiating salam, and the reply wa alaykum.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.