'Iron' in the Bible

He will cut down the thickets of the forest with iron, and Lebanon will fall by the Mighty One.

"I will go before you, and make the rough places smooth. I will break the doors of brass in pieces, and cut apart the bars of iron.

Because I knew that you are obstinate, and your neck is an iron sinew, and your brow brass;

For brass I will bring gold, and for iron I will bring silver, and for wood brass, and for stones iron. I will also make your officers peace, and righteousness your ruler.