Histories

This king (they told me) had great wealth in silver, so great that none of the succeeding kings could surpass or come near it. To store his treasure safely, he had a stone chamber built, one of its walls abutting on the outer side of his palace. But the builder of it shrewdly provided that one stone be so placed as to be easily removed by two men or even by one.

So when the chamber was finished, the king stored his treasure in it, and as time went on, the builder, drawing near the end of his life, summoned his sons (he had two) and told them how he had provided for them, that they have an ample livelihood, by the art with which he had built the king's treasure-house; explaining clearly to them how to remove the stone, he gave the coordinates of it, and told them that if they kept these in mind, they would be the custodians of the king's riches.

So when he was dead, his sons got to work at once: coming to the palace by night, they readily found and managed the stone in the building, and took away much of the treasure.