I read the following Fatwa by Mufti Ibraaheem Desai regarding Tawassul. Please let us know whether what they are stating is true.
Imaam Nawawi, may Allaah have mercy on him, has mentioned that from among the etiquettes of visiting the grave of Rasulullaah, sallallaahu alayhi wa sallam, one should make Tawassul through Rasulullaah, sallallaahu alayhi wa sallam, to Allaah to accept his Du’a. Thereafter, Nawawi states, ‘…and one of the best things that one should do is what has been related by Al-Mawardi, Al-Qaadhi Abu Teeb, may Allaah pleased with them, and all our Ulama and they have all regarded it as commendable, and that is the incident of Imaam Al-Utabi, may Allaah have mercy on him, that he said, ‘I was once seated by the grave of Rasulullaah, sallallaahu alayhi wa sallam, when a Bedouin came and said, ‘Peace be upon you, oh, Messenger of Allaah. O Messenger of Allaah, I have heard Almighty Allaah says in the Qur’aan: “And if they, when they had been unjust to themselves, had come to you (Muhammad, sallallaahu alayhi wa sallam) and begged Allaah’s forgiveness and the Messenger had begged forgiveness for them, indeed they would have found Allaah All-Forgiving. Most merciful. [4:64] hence, I have come to you in a state that I seek forgiveness of my sins by seeking your intercession by my Lord’, thereafter he recited a few couplets and departed. Imaam Al-Utabi states, ‘I then fell asleep and I saw Rasulullaah, sallallaahu alayhi wa sallam, instructing me by the words, ‘O Utabi, go to that Bedouin and give him the glad tidings that Almighty Allaah has forgiven him.’ (Refer al-Majmoo vol.8 pg.456 – Cairo and Manaasikul-Imaam-Al-Nawawi pg.498-499 Maktabah Salafia). This incident has been related by many Ulama in their respective compilations. Some of them are: Hafiz Ibn-Katheer in his Tafseer, Abu-Muhammad Ibn Qudaamah in Al-Mughni vol.3 pg.556, Imaam Abul-Faraj in Al-Sharhul-Kabeer vol.3 pg.495, etc.

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 is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

Many scholars have stated the story of Al-Utabi in relation to seeking intercession of the Prophet but it is not an authentic story. The author of the book 'Siyaanat Al-Insaan' said: 'This is a objectionable and fabricated narration and we cannot rely on it.' Moreover, Ibn Taymiyyah said in one of his books that addressed intersession after referring to this story: "None of the scholars of the four schools or any others who people follow the opinion of have stated this. Moreover, those who have stated this story have not stated a religious evidence proving it. It is known that if asking for a supplication, intercession or his (Prophet's) forgiveness is allowed at his grave, the companions and the righteous predecessors who followed them exactly in faith, would have been more knowledgeable about it and would have been the first to precede us in this matter. Besides, if this matter is permissible, the Muslim scholars would have stated it. Verily, Imaam Maalik made a magnificent statement as he said: 'The last of this nation would not be righteous and steadfast except by following what the first generation of this nation were upon.'

Allaah Knows best.