Is there any Specific Wording to use when sending Prayers upon Him at His Grave, and does He see the One Who gives Salutations to Him, and has He extended His Hand to any of the Companions or Anyone else?

Question :

Which prayers are better at his noble grave, I mean: "Peace and blessings upon you, O Prophet!" or: "O Allah! Send blessings upon Muhammad and upon the family of Muhammad." - in the form of a request? And does the Prophet look at the man who sends blessings upon him at his noble grave? And has the Prophet extended his hand from his noble grave to any of the virtuous Companions, or to the honorable Awliya', in answer to their salutations?

Answer:

(a) No particular formula has been authentically reported from the Prophet so far as we know - for sending salutations of peace and blessings upon him at his grave, therefore it is permissible to say, when visiting him:
"As-Salaatu was-Salaamu 'alayka ya Rasoolullaah."

or: "Blessings and peace be upon you, O Messenger of Allah." - because the meaning of this is a request, even though the wording may suggest it is a statement. It is also permissible to greet him, with the salutation of Ibrahim, upon him be peace, saying:
"Allaahumma Salli 'alaa Muhammad..."
"O Allah! Send blessings upon Muhammad..." etc. But it is better to send salutations of peace upon him in the form of a statement, in the same manner in which one sends salutations of peace upon the other graves, and because when Ibn 'Umar, may Allah be pleased with him, used to visit him, he would say:
"As-Salaamu 'alayka ya Rasoolullaah, as-Salaamu alayka ya Abu Bakr, as-Salaamu 'alayka ya abataah."

"Peace of Allah be upon you, O Messenger of Allah! Peace of Allah be upon you, O Abu Bakr! Peace of Allah be upon you, O my father!" Then he would leave.

(b) It has neither been recorded in the Book (of Allah), nor the authentic Sunnah, that the Prophet sees those who visit his grave, and the fundamental belief is that he does not, in the absence of any evidence to the contrary from the Qur'an and Sunnah.

(c) Essentially, a dead person - whether Prophet or otherwise - does not move in his grave, by stretching out his hand, or any other movement. So whatever has been said concerning the Prophet stretching out his hand to some of those who greet him is not authentic; indeed, it is pure fancy and imagination, without any basis in fact.

Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 1 Pages 277-278