'Grain' in the Bible

But they have no knowledge of the thoughts of the Lord, their minds are not able to see his purpose: for he has got them together like stems of grain to the crushing-floor.

Up! and let the grain be crushed, O daughter of Zion, for I will make your horn iron and your feet brass, and a number of peoples will be broken by you, and you will give up their increase to the Lord and their wealth to the Lord of all the earth.

You will put in seed, but you will not get in the grain; you will be crushing olives, but your bodies will not be rubbed with the oil; and you will get in the grapes, but you will have no wine.