'Rod of Iron' in the Bible

And he shall rule them with a rod of iron; as the vessels of a potter shall they be broken to shivers: even as I received of my Father.

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

And out of his mouth goeth 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 and wrath of Almighty God.