I'll kill ya.

If you hold back anything, I'll kill ya. If you bend the truth or I think you're bending the truth, I'll kill ya. If you forget anything, I'll kill ya. In fact, you're gonna have to work very hard to stay alive, Nick. Now, do you understand everything I've said? 'Cause if you don't, I'll kill ya.

Lock, Stock and Two Smoking Barrels (1998), Guy Ritchie.