eat dirt - When you tell someone to eat dirt, you're basically saying,

When you tell someone to eat dirt, you're basically saying, 'Leave me alone, or I'll make you eat dirt.'

I told him to eat dirt. He didn't leave. So I told him to eat dirt again.

She kept bugging me. I told her to eat dirt. She left.

He was annoying. I said, 'Eat dirt, and leave me alone.'