unless there is some link between the supplicant and the persons invoked: either his love for them and obedience to them—for which he is rewarded—or their praying on his behalf, in which case Allah accepts their intercession for him (1).
[Seeking a means through the prophets and the righteous is achieved either by obeying and following them, or by benefiting from their supplication and intercession.]
Therefore, tawassul through the prophets and the righteous takes two forms: (i) obeying and following them, or (ii) obtaining their supplication and intercession. Merely calling upon them, without obeying them oneself and without their interceding, brings no benefit, even though any one of them may enjoy the highest rank with Allah (2).
I have discussed these matters in detail elsewhere (3).
The purpose here is this: if the early generations and the leading scholars have already ruled on asking a living creature in the manner previously described, what then of asking a creature who has died—whether one asks him to petition Allah, or asks him directly to fulfill a need, and the like—practices some people perform either at the grave or while the deceased is absent? The Lawgiver—peace and blessings be upon him—cut off the root and blocked the means by cursing those who take the graves of prophets and righteous folk as places of worship, by forbidding prayer beside them for Allah’s sake, and by enjoining that supplication be directed to Allah alone. He warned his community against all of that. How much worse, then, when the very evil he feared—idolatry and its causes—has actually occurred? The prohibition of praying at graves and turning them into mosques has already been discussed.
It has also become clear that none of the Salaf ever practiced such acts, apart from what is reported of Ibn ʿUmar: he would deliberately camp where the Prophet—peace and blessings be upon him—had camped and pray where he had prayed; indeed, when the Prophet performed ablution and poured the remainder of his water at the foot of a tree, Ibn ʿUmar did the same. This was simply Ibn ʿUmar’s careful imitation of the Prophet’s actions: he intended only to do what the Prophet had done with respect to his stopping places, his prayers, and his pouring out of water and similar matters. Ibn ʿUmar did not intend to pray or supplicate in those spots because of their location (4).