'Grinding' in the Bible

In that place there will be weeping [in sorrow and pain] and grinding of teeth [in distress and anger] when you see Abraham and Isaac and Jacob and all the prophets in the kingdom of God, but yourselves being thrown out and driven away.

There will be two women grinding [at the mill] together; the one (the non-believer) will be taken [away in judgment] and the other (the believer) will be left.