The ruling on praying in a mosque built with doubtful funds

Question:
A man built a mosque with money from his mother, who works in fortune-telling, sorcery, and slaughtering for other than Allah. He says: "We worship Allah, we fast, we pray, we perform Hajj, and other acts of worship."
The question is: Is it permissible to pray in this mosque? And what is the ruling on what the imam and the mu'adhdhin receive in this mosque?

Answer:
In mosques built with doubtful funds and forbidden funds, the prayer is valid. Invalid funds are to be spent on avenues of good and good deeds, such as for the poor, the needy, and the mujahideen, and for the development of charitable projects. This is because such funds are like lost funds; they are to be spent on what benefits the Muslims. The sin is upon the one who committed the act, and the benefit is for the Muslims. They are not to be burned or thrown into the sea, but rather spent on the interests of the Muslims, including mosques.
However, if good funds are available for the mosque, that is better and more pure. But if such funds are spent on a mosque, it does no harm; no, it does not harm the worshippers. The sin is upon the one who dealt in them and earned them. But if he spends them on building the mosque, or on medicine, or on restrooms, or on other interests of the Muslims, such as repairing roads, or otherwise, or for jihad, then this is something that mitigates the sin for him.