If prayer in a mosque containing a grave is not permissible, does this mean it is invalid?

The questioner : Your Eminence, if prayer in a mosque containing a grave is not permissible, does this indicate that it is invalid and not accepted? And is there evidence for its invalidity, if it is indeed invalid?

The Shaykh : Yes. First: regarding a mosque containing a grave, one must look to see whether the mosque was built on the grave, or whether it existed previously and the deceased was buried in it. As for the first case: prayer in it is not valid, because it is a place where staying is forbidden, and it is not valid for anyone to pray in a place that is forbidden for them, especially in matters related to worship. This is because a mosque built on a grave leads to the exaltation of the grave's occupant. To block the means to shirk (associating partners with Allah), we say: it is haram (forbidden), the one praying is sinful, and his prayer is not valid. The evidence is the saying of the Prophet (peace and blessings be upon him): And prayer in mosques built on graves is prohibited without a doubt. If the Prophet (peace and blessings be upon him) said: meaning "do not make them your qiblah (direction of prayer)," then what about one who prays in a mosque built on a grave? As for if the mosque existed before the grave and the deceased was buried in it: if the deceased is in the direction of the qiblah, it is not permissible to pray toward him, but one must turn to the right or left of him. If the deceased is not in the direction of the qiblah, there is no harm. However, in this case, it is obligatory to exhume the deceased and bury him in the place where people are buried. Yes.