What is the ruling on one who claims to have seen the Prophet while awake, and claims that praying in mosques that contain tombs is a Sunnah and is recommended, citing the Hadith of Abu Basir? And how can people be warned against his fatwas?

The ruling on prayer in a mosque that contains a grave has been clarified, along with a refutation of the argument based on the hadith of Abu Jandal, and the impossibility of seeing the Prophet (peace be upon him) according to verified scholars. Students of knowledge should teach Muslims religious knowledge with its proofs and clarify the refutation of specious arguments presented to the common people with sound evidence.