Anything you say can and will be used against you

I never saw no bag of it. No way!
It must be yours, not mine. I see you laugh,
You git! I hardly touch the stuff, unless
It’s Christmas Day, when Mother puffs it good.

It might be herbs. Some dill or thyme for lunch.
Not what you say. It’s grass—some lawn somewhere
Is missing some. You look! I need to eat.