That sounds like a flavor of the old “Stone of the Unbroken Pact” tales that pop up in the eastern desert myths. In one version, the stone lies at the edge of the Shimmering Wastes, its surface unchanged for centuries, and the only way to unlock its secrets is to recite the ancient covenant that first bound the desert peoples. A similar legend is the “Perpetual Obelisk” of the desert city of Kharim, where scholars say the stone keeps its original inscriptions even after a thousand years of sandstorms. Both stories usually hint that the stone isn’t just a relic—it’s a living key that remembers every promise made beneath the dunes.