If some of the workers in a company are disbelievers and some are Muslims, is it permissible or not?

The questioner : Peace be upon you.
The Shaykh: There is expatriate labor.

The Shaykh : Yes

The questioner : There is expatriate labor.

The Shaykh : What kind of work?

The questioner : Expatriate labor.

The Shaykh : The expatriate.

The questioner : Expatriate workers.

The Shaykh : The expatriate, yes.

The questioner : And we do not know who is Muslim and who is a disbeliever, so how do we deal with them regarding the greeting of peace?

The Shaykh : Greet the one you think is Muslim. For example, if the workers here in this company are mostly Muslims, then greet them. If they are mostly disbelievers, do not greet them. However, some scholars say that if you say "Good morning" or "Welcome, so-and-so," this is not a salam (greeting of peace), because the Messenger (peace and blessings be upon him) said: And the salam is a supplication, unlike "Welcome, so-and-so" or "Hello, so-and-so," which is a greeting and not a salam. So if you fear that he is a Muslim and something might affect his feelings, say to him: "Welcome, so-and-so." In that case, you will not fall into sin, even if it turns out that he is a disbeliever. But do you say: "Are you a Muslim so I greet you, or a disbeliever so I do not greet you?" I am asking you.

The questioner : ...

The Shaykh : No... everyone knows that it is a mistake.