…be concentrated as I have told you, then you open yourself as one opens a door; you see, you have a door here (gesture at the level of the heart) and once you are concentrated, you open the door and stay like this (gesture of immobility). Or else, you may take another image, as if it were a book, and you open your book very wide with its pages completely blank, that is, quite silent, and you stay like that waiting for what is going to happen.
Ref: Questions and Answers 1957–1958