What is the ruling on opening a door on the right side of the mosque from one of the windows to place the deceased outside, and the Imam prays over it from inside the mosque?

Praying over the deceased in the mosque is a matter of disagreement among scholars, with the majority permitting it. However, some have disliked bringing the deceased into the mosque and praying over them there. This is the view of the Malikis, who consider it disliked to pray over a funeral inside the mosque, even if the bier is outside.

As for the Hanbalis, they have stipulated that praying over a funeral before burial from behind a barrier, such as a wall, is invalid. Based on this, there is no need to open a door in the mosque for the purpose of praying over a funeral in the manner mentioned, as some consider it disliked, and others deem it invalid when performed from behind a barrier.

Therefore, either the deceased is brought into the mosque for prayer (which is permissible according to the majority), or the prayer is performed in prayer areas outside the mosque (which is a matter of consensus and largely consistent with the guidance of the Prophet, peace be upon him).