You must on no account attempt to use the squares given in...

You must on no account attempt to use the squares given in the Book of the Sacred Magic of Abramelin the Mage until you have succeeded in the Operation. More, unless you mean to perform it, and are prepared to go to any length to do so, you are a fool to have the book in your possession at all. Those squares are liable to get loose and do things on their own initiative; and you won't like it.