—who claims affiliation with Islam yet holds a heresy that expels one from the faith. Such a person is not to be greeted with peace, for he is unworthy of it. For that reason the Prophet (peace and blessings be upon him) said, “Do not initiate the greeting of peace with the Jews or the Christians.”

A Muslim should also raise his voice enough to be heard and must not “greet with his nose.” Some people—may Allah guide us and them—are either proud or harsh; when they meet you they mumble a greeting under their breath so faintly that you can hardly hear it. This runs contrary to the concept of spreading the greeting.

To disseminate the greeting means to say it aloud and clearly: as-salāmu ʿalayk (“peace be upon you”).

The scholars add one exception: if you greet a group in which some are awake while others are sleeping, you should not raise your voice to the point that it wakes the sleepers, for that would cause them harm.

The preferred wording is as follows:
• When addressing one person: as-salāmu ʿalayk.
• When addressing a group of men: as-salāmu ʿalaykum.
• When addressing a group of women: as-salāmu ʿalaykunna.

When you say as-salāmu ʿalayk, ʿalaykum, or ʿalaykunna, you are in fact praying for their safety and well-being. The phrase is not a mere formality; it is a supplication that Allah safeguard them from every harm—sins of the soul, diseases of the heart, bodily afflictions, and attacks on one’s honor. For this reason, if you say only “ahlan wa marḥaban” (“welcome, glad to see you”) in place of the greeting, it does not suffice. Although such words convey courtesy and congratulations, they contain no supplication.

Therefore, the legislated greeting is to say: as-salāmu ʿalaykum.