'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 in pieces; as I also have received of my Father;

And she brought forth a male 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 He may smite the nations therewith: and He shall rule them with a rod of iron: and He treadeth the wine-press of the indignation and wrath of God almighty.