'Brass' in the Bible

"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.