Edward was lying on his stomach because his back was all injured and bleeding as well as his shoulders. He was struggling to breathe and move.
He wanted to get up and shower as well as put some ointment on his wounds but could not move because of how much pain he was feeling in his back.
The punishment was so hard on him and the three days that he spent in the underground jail were a real image of hell on this earth.
His and Isaac's punishment was to get lashed a hundred times on their back every single morning for three days which is why their back was filled with blood and wounds.
"Oh my God, Edward!!!!" Although Edward heard Luther coming inside the room he could not move or say anything because he was busy burying his face in the pillow trying to endure this pain.
Luther the moment he entered the room, he got shocked as he gasped loudly and put his hand on his mouth while looking at Edward's back in disbelief. The view was traumatizing.
