'Rod of Iron' in the Bible

and he shall rule them with a rod of iron, as the vessels of the potter are broken to shivers; as I also have received of my Father:

And she was delivered of a son, a man child, who is to rule all the nations with a rod of iron: and her child was caught up unto God, and unto his throne.

And out of his mouth proceedeth a sharp sword, that with it he should smite the nations: and he shall rule them with a rod of iron: and he treadeth the winepress of the fierceness of the wrath of God, the Almighty.