http://www.forrestrace.com/saw-glass-3/

In the first Saw a man is sorrounded by glass, standing naked with red numbers everywhere?
How was he supposed to escape? Why was he there? Wouldn’t it be impossible to solve the combination with so many numbers? Why was he blasted with fire? Keep in mind I’ve only seen 1& 2 at my uncle’s house. And I couldn’t hear very well, because we had to keep the volume low.
He was supposed to figure out the combination of the safe using the numbers on the wall. But he was covered in gasoline and the only way he could see the numbers on the wall was with a candle. The key to leave the room was inside the safe.
I think he was there because he was an arsonist, someone who likes to start fires. So he sort of got a taste of his own medicine.
Using a Glass Saw