The Tibetan Book of the Dead

Said to have its origins in the "treasure text" that were supposedly hidden away by Padmasambhava, the Lotus Guru, in Tibet in the 8th century. The Tibetan book of the Dead was traditionally read aloud to the dying or recently deceased as a guide to the after life.  

It explains how to recognize the true nature of the mind so that after death it will be possible to attain enlightenment and liberation from the suffering associated with the endless cycle of death and rebirth