You could say: "Oh, you're leaving? Well, don't dally in the doorway, because I'm going to slam the door after you, and it might bruise your ass or even break an ass-bone if you aren't quick enough." How does that sound?
No. From the way people used the phrase 50-60 years ago, I got the strong impression that they were talking about a door with a spring. Neither people nor their argot were quite as rude as we are today.
Fire regulations. Heavy steel or solid wood fire doors are meant to be kept closed (except when somebody is actually going through them) to prevent fires from spreading quickly through a building.
Most expressions are older than we think. I wouldn't be surprised if Shakespeare used it. Please Register or Log in to view the hidden image!