The Ruling on Praying in a Mosque That Contains a Grave

Question:
Honorable Shaykh, Abdullah al-Sudan built a mosque with the help of one of the Muslims. Before the mosque was completed, the person who was overseeing it died, so his family buried him in the structure of this mosque. Now the mosque has been completed and they are holding Friday prayers in it, and the people are praying the line of the sermon. Finally, it was placed on the side of the external structure that the prayer in this mosque is not valid.

Answer:
If the grave is inside the mosque, the prayer in it is not valid, and it is obligatory to dig up the grave. The grave is dug up and moved to the Muslim cemeteries, buried with the Muslims, and kept away from the mosque. If the grave was the original structure and the mosque was built on top of it, then the mosque is demolished, because it is a later addition. But if the mosque was the original structure and the deceased was buried in it afterwards, then the grave is moved and the mosque remains. However, having a mosque and a grave together is not permissible in Islam.