'Grinding' in the Bible

Then the king said to the servants, 'Bind him hand and foot, take him away, and throw him into the outer darkness; there is where the weeping and grinding of teeth will be.'

two women grinding at the mill, one will be taken and one will be left.

and will cut him in pieces, and appoint his portion with the hypocrites. There is where the weeping and grinding of teeth will be.