The Yashuvhi sacred scroll was a piece of parchment that had been passed down through the Yashuvhi culture on Yashuvhu. It was a document that had become worn with age, being weathered by the time of the planet's rediscovery by Pathfinder III. The document contained a portion of the Jedi Code inscribed by a Jedi who had become marooned on the planet sometime during the Old Republic. The scroll eventually fell into the possession of one of the Jedi's descendants, the Force Adept Valara Saar.
Sources
Meet Valara Saar: Force Adept on Wizards.com (original site is defunct)