Is it a condition for the validity of the funeral prayer that the deceased be placed on the ground, or is it permissible to pray over him while he is on a bed or similar?

There is no harm in praying over a deceased person while they are on a bed or stretcher, as these are stable and do not rise above the heads of the worshippers. This differs from praying over a deceased person who is being carried on an animal or on people's hands, which some scholars prohibited because the deceased is in the position of an imam, and it is not permissible for him to be carried while they (the worshippers) are on the ground.

Shaykh al-Islam Ibn Taymiyyah said that praying over a deceased person being carried on men's necks and standing still has two considerations: the stability of the place, and the condition that the worshipper be aligned with the deceased.