God is making a way for the faithful to obey Him. He is breaking in pieces the gates of brass and cutting asunder the bars of iron. This is “prelude” to the wealth transfer. God will make His enemies pay for the what His people have suffered. Some will even pay with their lives, and God’s people will be rewarded with the wealth and the position of those who plotted against them.
“I will give you the treasures of darkness And hidden riches of secret places,
That you may know that I, the LORD, Who call [you] by your name, [Am] the God of Israel.” Isaiah 45:3 NKJV