'Millstones' in the Bible

“Take millstones [as a female slave does] and grind meal;Remove your veil, strip off the skirt,Uncover the leg, cross the rivers [at the command of your captors].

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 [grinding meal] and the light of the lamp [to light the night].

Young men worked at the grinding mill,And boys fell [staggering] under loads of wood.