It's not "not allowing someone to pay". It's "not providing service to someone out of a hurried promise of later payment". What restaurant will kindly let you

It's not "not allowing someone to pay". It's "not providing service to someone out of a hurried promise of later payment". What restaurant will kindly let you pay them next Tuesday for a hamburger today? And sadly, no - if you're a homeless person and walk into most hospitals with cancer, you'll get some painkillers if you need them (before being sent on your way), not a walk to the oncology ward.