What is the ruling on visiting the graves of the righteous and supplicating to Allah there for blessings, with the belief that all matters are in Allah's hands, and that this may be a reason for the supplication to be answered as a veneration for the righteous person or through his intercession?

Intending to visit a grave to supplicate there, or believing that doing so makes supplication more likely to be answered, is among the innovations (bid'ah) against which scholars have warned. This is because it is a newly invented act that was not performed by the righteous predecessors (Salaf al-Salih).

Ibn Taymiyyah states that an innovative visit (Ziyarah Bid'iyyah) is one intended for seeking needs from the deceased, or seeking supplication and intercession from them, or supplicating at their grave with the belief that this makes the supplication more likely to be answered. All of this is an innovation and part of shirk (polytheism).

Ibn al-Qayyim adds that supplicating to the dead, or supplicating by means of them, or supplicating at their graves, was neither prescribed nor considered a righteous act by the three favored generations. He questions how this could be prescribed when the Companions and their Successors neglected it, despite their eagerness for every good.

As for visiting the grave of the Prophet (peace be upon him), it is not for the purpose of supplicating there. Ibn Taymiyyah affirms that the Salaf did not intend to supplicate at the graves of prophets or others. Rather, they would pray and send greetings upon the Prophet (peace be upon him) and his two companions. The imams have agreed that one should not face the grave when supplicating in the Prophet's Mosque.