Answered by Shaykh Faraz Rabbani
Question: As salam alaykum,
Many people go to a tomb of a saint and ask for a child or a job. Some may even prostrate in its direction. Is it tawassul? Is building a shrine over a grave ok? Can the saint help from his grave? What is the meaning of calling out a saint?
Answer: Walaikum assalam,
I pray this finds you in the best of health and spirits.
Tawassul itself is making dua to Allah Most High, Himself, through the means (wasila) of one of rank and regard with Him—such as the Prophet (peace and blessings be upon him). Its basis is from the Qur’an itself, from Allah’s call to, “Seek a means (wasila) to Him.” [Qur’an, 5.35] And it is established from a number of hadiths of the Prophet (peace and blessings be upon him), including the “Hadith of the Blind Man.”
Shaykh Nuh Keller writes:
Tirmidhi relates, through his chain of narrators from ‘Uthman ibn Hunayf, that a blind man came to the Prophet (Allah bless him and give him peace) and said, “I’ve been afflicted in my eyesight, so please pray to Allah for me.” The Prophet (Allah bless him and grant him peace) said: “Go make ablution (wudu), perform two rak’as of prayer, and then say:
اللَّهُمَّ إِنِّي أَسْأَلُكَ وَأَتَوَجَّهُ إِلَيْكَ بِنَبِيِّكَ مُحَمَّدٍ نَبِيِّ الرَّحْمَةِ ، يَا مُحَمَّدُ إِنِّي تَوَجَّهْتُ بِكَ إِلَى رَبِّي فِي حَاجَتِي هَذِهِ فَتُقْضَى لِي ، اللَّهُمَّ شَفِّعْهُ فِيَّ
“Oh Allah, I ask You and turn to You through my Prophet Muhammad, the Prophet of mercy; O Muhammad (Ya Muhammad), I seek your intercession with my Lord for the return of my eyesight [and in another version: “for my need, that it may be fulfilled. O Allah, grant him intercession for me”].”
The Prophet (Allah bless him and give him peace) added, “And if there is some need, do the same.” See the full Answer here: Tawassul: Supplicating Allah through an Intermediary
The Other Issues Mentioned
As for the other issues mentioned, we have to distinguish between what is soundly established from Prophetic teachings, as understood by mainstream scholars—as represented by the four schools of Islamic law (fiqh)—and popular practices that may mix sound and unsound matters. This includes visiting graves (a recommended sunna) itself, as opposed to some questionable practices that may be found in some contexts.