I take no prisoners.

He who opens a school door, closes a prison.

We are prisoners of our own metaphors, metaphorically speaking.

The first prison I ever saw had inscribed on it ‘cease to do evil: learn to do well’; but as the inscription was on the outside, the prisoners could not read it.

In some ways, we are traveling in time now. We just happened to be prisoners of the present in the eternal transition from the past to the future.