Star Wars has introduced an ancient Jedi ritual, one presumably forgotten in the mists of time. So many secrets of the Jedi were lost when Palpatine established the Empire; the Emperor knew the Jedi were the only possible threat to his reign, and so he did his best to erase all records of them. That means so many secrets of the Order, including the origin and history of the Jedi, were erased from history. Still, recent Star Wars books and comics have begun revealing some of these secrets, stepping back to a time centuries before the events of Star Wars: Episode I - The Phantom Menace.
George Mann's novel Quest for the Hidden City is the latest in this range, set 350 years before the prequel trilogy. It stars two Jedi, Silandra Sho and her Padawan, Rooper Nitani, and in one scene Silandra mentions an intriguing Jedi ritual performed during this era. "I intend to make a pilgrimage to Jedha," Silandra tells her apprentice. "When circumstances allow. It's been many years since I observed the Season of Light and looked upon my reflection in the kyber mirrors beneath the Dome of Deliverance. I think it might be time."
Why The Jedi Revered The Planet Jedha
Introduced in Rogue One: A Star Wars Story, the Temple Moon of Jedha was considered sacred to many orders of Force sensitives. Star Wars: The High Republic comics have revealed it was actually once ruled by the Jedi, a planet set apart from the Republic for pursuit of spiritual growth. Presumably the Jedi moved away from Jedha to Coruscant as they became more closely bound to the Republic; still, the Temple Moon remained important to the Jedi, with some of their number traveling there to conduct rituals that must have dated back to the time it was their order's home.
Silandra's Season of Light has never been mentioned before, but it's easy to guess what it must involve. Kyber crystals are powerful in the Force, and presumably a kyber mirror is able to grant a person insight into their own character and nature, revealing truths of their being they would otherwise be ignorant of. Silandra mentions wanting to go back to Jedha in a moment of introspection, suggesting she believes this pilgrimage is necessary to help her grow in the light side of the Force.
Jedha's Destruction Ended So Many Jedi Rituals
Jedha was rich in deposits of kyber, which made it particularly valuable to the Empire, who stripped the planet of the precious mineral to power the Death Star. Previous tie-ins have already revealed the Empire took almost all kyber from the temples as well, presumably meaning the kyber mirror Silandra hoped to gaze in wound up being integrated into the Imperial superweapon. Such an act of sacrilege underscores the darkness of the Death Star, with the Empire turning something pure into a weapon with which to destroy entire worlds. The Death Star was ultimately used to destroy Jedha, and the Dome of Deliverance itself was consumed. Sadly, this particular Jedi ritual has been lost in the Star Wars galaxy.