Out Of A Mouth

Riddle: Out of a man's mouth it comes forth, lightening hearts and inspiring souls to be steadfast. Tales of old it tells, of warriors and kings, of castles and dungeons. It tells of sunshine and hills, flowers and grass. Of food and drink it encourages you to press on, of fantasies it gives you rest and delight. It carries on through ages and never an ending does it find. What is it?