In a city where masks are mandatory.

Grocery Store Clerk: Excuse me sir but you aren't allowed to shop here in order to put food on your table for yourself and your family unless you wear a mask. That is unless the reason for not wearing one is related to a medical condition.

Free Man: I'm not wearing a mask because you have a medical condition. You are suffering from an acute form of enslavement as indicated by your symptom of subservience to the state's authority over the issue of mask wearing. By not wearing a mask I am helping to cure your medical condition.