How long would you be in the hospital after a stab wound?

It's hard to say how long someone would stay because everyone's recovery time can vary. I think anything more than 3 inches can be deadly so they might just want to keep an eye on him and make sure that he is on the proper healing cycle. Also, they might want to hold him to ask him questions about why he was stabbed and if he is in danger again when he gets out. If his lung would've been stabbed then it would have deflated and he would have a very difficult time breathing (1 lung) and they'd have to plug it ASAP. Also organs and arteries are two different things. Good luck. :)