(Extract from a lengthy question) My question lies in another kind of Tawassul, and this form of Tawassul is when one does Ziyarat at the blessed grave of our Prophet [Sallallahu `Alayhi WaSallam] and asks him [Sallallahu `Alayhi WaSallam] to pray to Allah on our behalf for forgiveness, is this correct? My questions are summed up below:
 Is such Tawassul allowed?
 If it is allowed, then should it be practiced by everyone or the learned one who kmow the science behind should pratice it.
It would be helpful if you can clear this issue in light of the Hanafi Maddhab, or even Junhoor e Fuqaha of the Other Madhaahib.
In the name of Allah, Most Compassionate, Most Merciful.
Allah states in the Quran: “O you who believe! Fear Allah and seek a means (wasila) to be closer to him…” (Surah Maida: 35)
In another ayah Allah states: “…If they would have come to you when they had wronged themselves to seek Allah’s forgiveness and if the Rasool had also asked Allah’s forgiveness for them, they would have found Allah Forgiving, Merciful.. (Surah Nisa: 64)
It is clear from the above verses that tawassul is permissible and there is no difference between the living and the dead in this matter. However there is difference of opinion of the scholars in the tawassul mentioned above in your question. This difference stems from the fact that do the dead hear the living.
The scholars who are of the opinion that the deceased cannot hear present the ayah “The fact is that you cannot make the dead hear you…” (Surah Naml: 80) as their eveidence. On the other side the Hadith narrated by Ibn Umar is presented where The Prophet looked at the people of the well (the well in which the bodies of the pagans killed in the Battle of Badr were thrown) and said, “Have you found true what your Lord promised you?” Somebody said to him, “You are addressing dead people.” He replied, “You do not hear better than they but they cannot reply.” (Sahih Bukhari: 2.452) (see Fatawa Darul Uloom Doeband vol 5, P461& Ahsanul Fatawa, Vol 4, P191)
Apart from the above many Ahadiths for and against are submitted in evidence for both sides of the argument. In short this issue is debatable and undecided amongst the scholars and that is why you have the different statements as mentioned above. The most pious opinion and method is that the person asks Allah directly and if required through the status of his pious prophet or people and not the deceased (to pray to Allah on his/her behalf). As this could have an effect on the believes of the ordinary people, it is for this reason scholars state that it is undesirable for a person (ordinary individuals as well as scholars) to do dua with the words “bi haqqi rusulika” (right/status of the prophet) as the creation do not have any right over the creator. (Raddul Muhtar, Vol 5, P281) However the above versus clearly indicate the permissibility of tawassul, therefore, if one does use tawassul then one should be precautious in not having any wrong belief and should always remember that Allah alone has influence over everything.
And Allah knows best
Darul Ifta, Birmingham