The ruling on entering the Deceased through the Door of Mercy in (the Prophet's Masjid in) Al-Madinah instead of other Doors
Question :
Many of the people in Al-Madinah Al-Munawwarah have taken it as a custom to enter the deceased through the Door of Mercy only instead of the other doors (of the Prophet's Masjid). This is because they believe that Allâh will have mercy on him and forgive him because of this. Is there anything authentic concerning this from our pure Islamic law?
Answer:
I do not know of any basis for this belief in our accommodating Islamic law. Rather, it is an evil and it is not permissible to believe it. There is no harm in entering the deceased through any of the doors (of the Masjid). It is better to enter the body through the door that will cause the least harm upon those who are praying.
Source:
Ash-Shaykh Ibn Baz
Fatawa Islamiyah, Vol. 3 Page 112