'Millstones' in the Bible

and all the firstborn in the land of Egypt shall die, from the firstborn of the Pharaoh who sits on his throne, even to the firstborn of the slave girl who is behind the millstones; all the firstborn of the cattle as well.

The people would go about and gather it and grind it between two millstones or beat it in the mortar, and boil it in the pot and make cakes with it; and its taste was as the taste of cakes baked with oil.

“Take the millstones and grind meal.Remove your veil, strip off the skirt,Uncover the leg, cross the rivers.

Moreover, I will take from them the voice of joy and the voice of gladness, the voice of the bridegroom and the voice of the bride, the sound of the millstones and the light of the lamp.