What is the ruling on praying in a mosque that contains a grave?

It is not permissible to bury a deceased person inside a mosque, nor is it permissible to pray in a mosque that contains a grave within it, regardless of whether there is a special structure built over the grave or not, as this does not change the fact that it is a grave inside the mosque.

The imams have agreed that a mosque should not be built over a grave, and it is not permissible to bury a deceased person in a mosque. If the mosque existed before the burial, then the grave must be leveled or exhumed. If the mosque was built after the grave, then either the mosque must be removed or the appearance of the grave must be removed. Therefore, no obligatory or supererogatory prayers should be performed in a mosque that is built over a grave.

The Prophet, peace and blessings be upon him, forbade taking graves as places of worship and cursed those who did so. For this reason, the imams of Islam have agreed that it is not legislated to build a mosque over graves or to pray near them; in fact, many scholars consider prayer near them to be invalid.

Therefore, the mosque should be demolished if it was built over a grave, and the deceased should be exhumed if buried in a mosque, for a mosque and a grave do not coexist in the religion of Islam. However, if the grave is outside the mosque and separate from it, there is no harm in praying in the mosque.