Is it permissible to recite the remembrance (dhikr) authentically transmitted from the Prophet, peace and blessings be upon him, when passing by non-Muslim graves, without knowing if there is a Muslim grave among them?

When one passes by a graveyard, there are three scenarios:

1. If one predominantly believes it belongs to Muslims, then it is recommended to greet them with peace (salam).

2. If one predominantly believes it belongs to non-Muslims, then one should not greet them with peace. Rather, it is prescribed to give them tidings of the Fire.

3. If one has no predominant belief, then there is no harm in greeting them with peace, intending thereby to greet the Muslims among them.