Imâm Muhammad bin Sâlih bin `Uthaymeen (died 1421)
Majmoo`-ul-Fatâwâ (17/159-160)
Question: What is the correct position regarding praying the funeral prayer in a mosque?
Answer: The correct position is that it is okay to pray the funeral prayer in a mosque. The Messenger ﷺ prayed the funeral prayer for Suhayl bin Baydhâ’ in the mosque. (Muslim 973)