"See, I'm making you into a new, sharp, and multi-tooth threshing sledge. You'll thresh and crush the mountains, and make the hills like chaff.

It must be ground; one cannot keep threshing it forever. Even if he drives his cart and horses over it, he cannot crush it.

For caraway is not threshed with a sharp sledge, nor is a cart wheel rolled over cumin. Instead, caraway is winnowed with a stick, and cumin with a rod.