Job 41:30

Sharp stones are under him— His nether parts are like sharp potsherds. He dasheth himself on the mud like a threshing cart. Heath. חרוצ charutz, is rightly rendered by Bochart tribula, an instrument used in threshing of corn, a kind of sledge, furnished with sharp iron wheels. This was drawn over the straw by oxen, and at the same time thrashed out the corn, and cut the straw into small pieces, reducing it to chaff. An instrument of this kind is still used in the east for the same purpose. See Parkhurst on the word, and Observations, p. 142.