It was listed as a proverb in a publication from the 15th century, so presumably it had been around for some time even prior to that. It's unlikely, therefore, that you will ever establish who first said it...it may even date back to classical times. As suggested by Electrochem above, it means laying oneself open to punishment of one's own accord.
i thought it referred to a type of punishment/binding with a rod being strapped accross the shoulders with the arms attached so that the person can't move properly?
i know that sailors used to be made to make the whip that they were to be flogged with! and if they did a bad job of it lead weights were added (ouch!) this wont help you much sorry