mosque, and call upon Him with sincere devotion.’”
[Surah al-Aʿrāf: 29]
Allah Most High also says:
“It is not for the polytheists to maintain the mosques of Allah while bearing witness against themselves to disbelief. Their deeds have come to nothing, and they will remain in the Fire forever. The mosques of Allah are maintained only by those who believe in Allah and the Last Day, establish prayer, give zakat, and fear none but Allah. It is they who may rightly hope to be among the guided.”
[Surah al-Tawbah: 17–18]
Allah Most High also says:
“The mosques belong to Allah, so do not invoke anyone besides Allah.”
[Surah al-Jinn: 18]
There are many similar verses in the Quran.
Visiting graves takes two forms: the visitation of those who affirm Allah’s oneness and follow the messengers, and the visitation of the people of religious innovation and polytheism.
The purpose of the first is to greet the deceased with peace and supplicate for him. Visiting his grave is like performing the funeral prayer over him after his death, for its purpose is to supplicate for him. Allah—Glorious is He—rewards the person who supplicates for him at his grave just as He rewards the supplicant who performs the funeral prayer over him while he lies upon his bier.
The purpose of the second is to ask the deceased to fulfil one’s needs, to adjure Allah, or to suppose that supplicating to Allah at his grave is more likely to receive an answer. All of this constitutes reprehensible religious innovations by the consensus of the Muslim imams. None of it existed during the time of the Messenger—may Allah bless him and grant him peace—his Companions, or those who followed them faithfully.
Indeed, when the Muslims conquered Syria, Iraq, and other lands, whenever they found a grave that people frequented to make supplication beside it, they concealed it. When they found Daniel’s grave in Tustar, they dug thirteen graves for him by day and buried him at night in one of them. His grave had been exposed, and the unbelievers used it as a means of seeking rain. The Muslims therefore concealed it, because this is a form of polytheism. See the report and our comments on it at 1/480–481.