Claiming that supplications are more likely to be answered at graves is Bid’ah
10-4-2014 | IslamWeb
Question:
Assalamu alikum Could you please tell us what Imam ad-Dahabi said in Tareekh al Islam under the biography of Sultan bin Mahmood Balbaki the Zaahid. And in it he quoted a story by Shaykh Saaleh Mahmood bin Sultan. That Allah listened to the prayer at his grave. JazakAllahukhayran
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Moreover, the proof in understanding these texts lies within the understanding of the Companions and those who followed them in truth among the three first generations about whom the Prophet, sallallaahu ‘alayhi wa sallam, said: “The best people are those of my generation, and then those who will come after them (the next generation), and then those who will come after them (i.e. the next generation), and then after them, there will come people whose testimony will precede their oaths, and whose oaths will precede their testimony.”[Al-Bukhari and Muslim]
Ath-Thahabi mentioned this statement in the biography of that man, and he quoted narratives about him and then he said: “This is all that I have heard about this Shaykh, and I have doubt about their authenticity.”
Shaykh Al-Islam Ibn Taymiyyah 
explained that believing in the virtue of supplicating at the graves is an innovation, as he said in Majmoo’ Al-Fataawa:
“Innovations at graves are of degrees:
The furthest of those from the Sharee’ah is when a person asks the dead about his needs and seeks his help.
The second degree is to ask Allaah, The Almighty, by virtue of the dead; many of the later people do this and this is an innovation according to the consensus of the Muslims.
The third degree: believing that the supplication at the grave of the dead is answered, or that it is better than supplicating in the Masjid, so one intends to visit (that grave) and pray beside it to ask for whatever he needs. This is also among the evil innovations according to the consensus of the Muslims, and this is forbidden; and I am not aware of any difference of opinion about this among the Imaams of the Muslims, although many later people do so, and some of them say, the grave of so and so is 'a tried antidote'.” [End of quote]
He also said: “If a person says, the supplication is answered at the graves of Prophets and the righteous people, then this statement has no basis in the Book of Allaah and the Sunnah of His Messenger, nor was it said by any of the Companions or the Taabi’is (the generation that followed the Companions) who followed them well in faith; and no one among the Imaams of the Muslims who were renowned for their knowlege of religion, like Imaam Maalik, Ath-Thawri, Al-Awzaa'i, Al-Layth ibn Sa'd, Abu Haneefah, Ash-Shaafi’i, Ahmad ibn Hanbal, Is-haq ibn Raahawayh, and Abu ‘Ubaydah, said so; nor was it said by their Shaykhs who are followed as role models, like Al-Fudhayl ibn ‘Iyaadh, Ibraaheem ibn Adham, Abu Sulaymaan Ad-Daaraani and their like. Also, no Companions nor Taabi’is, nor early Imams used to say that the supplication is answered at the graves of Prophets and righteous people, neither generally nor individually...”
Allaah Knows best.