This worship carried out at graves falls under the heading of associating with Allah something for which He has sent down no authority, for Allah has revealed no proof that intentionally seeking out graves for supplication is recommended or possesses any special merit over other places. Whoever considers such a practice part of the religion of Allah is, in fact, speaking about Allah without knowledge.
How telling, then, is His statement:
“ … for which He has sent down no authority.” (Sūrat al-Aʿrāf, 7:33)
—so that no one may cite analogies or narratives as proof.
Along the same lines are His words relating the story of the Friend of Allah, Abraham:
“His people disputed with him, and he said, ‘Do you argue with me about Allah when He has already guided me? I do not fear what you associate with Him, unless my Lord wills otherwise; my Lord encompasses all things in knowledge—will you not take heed? And how should I fear what you associate, while you yourselves do not fear that you have associated with Allah partners for which He has sent down no authority? Which of the two parties has a better right to security, if you only knew? Those who believe and do not mix their faith with wrongdoing—it is they who shall have security, and they are rightly guided. That is Our proof which We granted to Abraham against his people. We raise in rank whom We will; surely your Lord is All-Wise, All-Knowing.’” (Sūrat al-Anʿām, 6:80-83)
The polytheists—whether their shirk is of the greater or lesser kind—seek to frighten the sincere with their so-called intercessors. They are answered: “We do not fear your intercessors, for they are merely creatures among the creatures of Allah; they cannot harm except by Allah’s permission. If He afflicts anyone with harm, none can lift it but Him; and if He shows mercy to anyone, none can withhold His favor. How, then, can we fear these created beings whom you have made intercessors while you yourselves do not fear Allah, having introduced into His religion forms of shirk for which He has…"