Is it permissible to pray in the Tijaniyyah mosque?

Question:
May Allah reward you, Honorable Shaykh. This questioner says: We are in an area where there is a mosque that people call the Tijaniyyah mosque. Is it permissible to pray in it? And should one pray in a mosque other than this one?

Answer:
This depends on the state of the mosque. If the mosque is built on a grave, then it is not permissible to pray in it, because the Prophet (peace and blessings be upon him) forbade praying at graves and forbade making graves into mosques, meaning places of prayer. However, if the mosque is free of a grave, there is nothing wrong with it, provided there are no apparent religious innovations (bid'ah) practiced in it. In that case, there is nothing wrong with praying the congregational prayer in it. If it is free of a grave and free of the apparent religious innovations practiced by the Sufis, then there is nothing wrong with praying in it. But if it contains religious innovations and newly invented matters, the Muslim should seek out a mosque that is free of religious innovations. Yes, yes. And if there is a grave in it, one must not pray in it under any circumstances. Yes.