What hope as given to people in his tomb saying arthur is the once king and king that will be?

The phrase "the once and future king" symbolizes the enduring hope and legacy of King Arthur, suggesting that he is not just a historical figure but a timeless leader who may one day return to unite and inspire his people again. This idea instills a sense of optimism and faith in a brighter future, emphasizing the cyclical nature of leadership and the belief that true greatness can transcend time. Arthur's tomb serves as a reminder that even in times of despair, hope for a noble and just ruler remains alive.