"It's purely academic." Gandalf interjected quickly before either of the dwarves could say anything to give away their real intentions for the quest. "As you know, these types of artifacts sometimes contain...hidden text."

Raising his eyebrows, as if he were not entirely convinced it were the truth but had no choice but to believe the wizard's explanation, Elrond walked to the edge of the cliff which the small group stood on, where a crystal like table stood. 
"These are Cirth Ithil, Moon Runes. They can only be read by the light of the moon at the same day and time that they were written on."
"Can you read them?" Thorin asked softly, almost holding his breath for fear that it was the wrong time. If they could not find out what those strange runes said they would never find the Hidden Door and retake Erebor from Smaug.
"Fate is smiling on you, Master Oakenshield." answered the elf Lord mildly as he glanced sideways at the dwarves. "The same moon shines upon us tonight."