i can't not smoke, and he doesn't notice the contradiction in his words- if you want to not smoke on the sabbath- but you smoke because you're incapable- so you're not free you're actually a slave to your smoking habits, you're enslaved to all kinds of desires or other things which your inner will tells you it wants to do such an such because it's the truth- but you are compelled and submissive to other forces to do other things. "and whoever accustoms himself to these habits..." meaning- that everything is sluggish and not quick to do what needs to be done in the right time, but rather everything on a physical level will be perfect