These are the spoken words required to retrieve the Necronomicon. If you do not speak the words "Klaatu Verata Necto" before picking up the Necronomicon, there will be hell to pay.
Ash attempts to pickup the Necronomicon, and fails to say the words "Klaatu Verata Necto". The demons below the earth wake and attempt to destroy Middle Earth. (see the movie "Army of Darkness" with Bruce Campbell).