Respect of the tombs of the Messenger of Allah (S) and the Holy Imams is Wajib in the view of all Muslims because every religious person considers their disrespect a greater sin. Many traditions speak of the respect necessary from the Tahzīb of Shaykh Mufīd.
The Messenger of Allah (S) addressed Amir ul-Mu’minīn (a.s.) and said,
“O ‘Ali! The Almighty Allah has made your grave and the graves of your progeny a section (piece of land) of Paradise. And gave it an exalted position. Allah has made the hearts of his pure-hearted and sincere servants to incline towards them. Those who bear all kinds of difficulties and insults for your sake. They shall habitate your shrines. They shall continue to visit them (do Ziarat) for the pleasure of Almighty Allah and for the love of His Messenger (S).
O ‘Ali! These very people will deserve my special intercession. On the day of Qiyāma they will arrive at my pool and shall be my neighbours. Those who carry out the construction of these tombs and come to visit them are like those who helped Hazrat Sulaiman (a.s.) in building the Baitul Maqdas. The reward of seven non-obligatory Hajjs is there for those who visit them. His sins will be washed off as if he has just emerged from the womb.
O ‘Ali! Good news to you! And to your followers of such bounties that eyes have not yet seen nor ears heard them. They have not even entered human imagination so far. But there shall be some disgraceful people who would insult, persecute and criticise the visitors to your graves like the criticism of a wanton female. They shall be the most mischievous people of my Ummah who would not receive my intercession and they shall never be able to reach my pool.”1
For detailed traditions on the subject please refer to Wafi, Wasa’il ul-Shia and Bihār al-Anwār Vol. 22.
The respect of the tombs of the Holy Prophet (S) and the Pure Imams (a.s.) is Wajib and a necessity of faith and their disrespect is a greater sin. In fact it is considered the greatest sin to the extent of Kufr and Shirk. If a tomb gets polluted and no disrespect is evident, on the basis of precaution, it is necessary to purify them.
According to jurists as in the case of mosques it is not permitted for Junub person, Haiz and Nifas ladies to stay in the holy Shrines. Some scholars even maintain that even passing through them is not permitted for polluted person, just as it is not allowed for Masjidul Harām.
t is not permitted to prostrate on the grave of any Imam (a.s.) during any Wajib or Mustahab prayer. But one can keep his right cheek on the grave. While praying near the grave we must keep it ahead of us and stand behind the head. Prayer is not allowed standing ahead of the grave because no one has the right to stand ahead of ones Imam. It is allowed to stand to the left or the right and to pray. That is we must not stand ahead or parallel to the grave).2
It is related from Hazrat Hujjat Ibn Hasan (a.t.f.s.) that prayers are not allowed ahead of the grave of a Masūm (a.s.), nor is it valid at the left or right of the grave because no one has the right to stand ahead or with the Imam. The writer of Wasa’il ul-Shia has explained the hadith prohibiting prayers to the left and the right side by saying that it is makrūh. (detestable).
Some scholars maintain that disrespect is caused only when the follower stands ahead of his Imam. But it is not a disrespectful act if he stands to the left or the right. However it is better to act on precaution.