Translation: Indeed Allah has forbidden the earth to devour the bodies of the Prophets.  The Prophets are alive and are given sustenance as well.  (Sunan Ibn Majah, Hadith No. 1706)

About the manners of visiting the Holy Prophet (Sallallahu alaihi wa sallam), the Hadith-experts and the jurists have said that when one goes there to present one’s greetings to the Holy Prophet (Sallallahu alaihi wa sallam), then one should face the blessed grave of the Holy Prophet (Sallallahu alaihi wa sallam), the back should be turned towards the Qibla (the direction in which Salaat is offered).  This is what Imam Malik (May Allah shower His mercy on him) had told Caliph Abu Ja’afar Mansur that when he visits the grave of the Holy Prophet (Sallallahu alaihi wa sallam), he should face the Holy Prophet (Sallallahu alaihi wa sallam) Himself.  There is a Hadith in Subul Ul Huda War Rashad:

Translation: When the second Abbasid Caliph Abu Ja’afar Mansur Abdullah Bin Muhammad Bin Abbas had a discussion with Imam Malik (May Allah shower His mercy on him), the Imam said:

O Commander of the faithful!  Don’t raise your voice in this Masjid, because Allah taught etiquette to a better community (i.e. the Companions) with the words:  Don’t raise your voices over the voice of the Holy Prophet (Sallallahu alaihi wa sallam).  Indeed, the way respect of the Holy Prophet (Sallallahu alaihi wa sallam) was necessary in His earthly life, it should be followed even after His demise.

The caliph became respectful and asked Imam Malik:

O Abu Ubaidullah!  Should I face the Qibla and supplicate or should I face the Holy Prophet (Sallallahu alaihi wa sallam)? 

Imam Malik said: How can you turn your face away from the Holy Prophet (Sallallahu alaihi wa sallam), when in Qiyamah, He (Sallallahu alaihi wa sallam) is the means (Wasila) in the court of Allah and the means of your father Hadhrat Adam (May peace be upon him)?  You should always turn to the Holy Prophet (Sallallahu alaihi wa sallam), as He is the one because of whom your supplication will be accepted for you.  Allah says: 

(Subul Ul Huda War Rashad, Vol. 11, Pg. No. 423)

Clarification of ‘Allama Ibn Taimiya

‘Allama Ibn Taimiya has clarified in this regard that when presenting one’s Salaam, we should face the Holy Prophet (Sallallahu alaihi wa sallam) and the back should be turned towards the Qiblah.  This was the practice of the Companions as well:

Translation: The Companions would present their Salaam in this manner only.  They would face the Holy Prophet (Sallallahu alaihi wa sallam) and turn their back towards the Qiblah.  This is the opinion of the majority of the scholars, like Imam Malik, Imam Shafa‘ee and Imam Ahmed Bin Hambal (May Allah shower His mercy on them).  (Mukhtasar Mansik Shaykh Ul Islam Ibn Taimiya)