Back to the Riotous Manacles of time

What on earth does this mean? I found it scribbled on a Post-It, stuck to the wall in the boiler room at work, tucked away in a corner where nobody would see it. I tried Googling it, but came up with nothing. It's got a vague John Milton or William Blake ring to it, though I am a complete ignoramus on that front.

Can anybody enlighten me?