" The story is that Odin travelled from home and came to a place where nine slaves were cutting hay. He asked if they wanted him to sharpen their scythes. They agreed. Then he took a whetstone from his belt and sharpened the scythes. To them it seemed that the scythes now cut much better, and they wanted to buy the whetstone. Odin set this price on the stone: he asked that whoever wanted to buy it should give what he thought was reasonable. They all said they wanted it and each asked to buy it, but instead he threw it into the air. They all scrambled to catch it with the result that they slit each other’s throats with their scythes. "

― Snorri Sturluson , The Prose Edda