O nobly-born... the body which you have now is called the thought-body of propensities. Since you do not have a material body of flesh and blood, whatever may come--sounds, lights, or rays--are, all three, unable to harm you; you are incapable of dying. It is quite sufficient for you to know that these apparitions are your own thought-forms. Recognize this to be the Bardo (the intermediate state after death).

(The Tibetan Book of the Dead)