Isaiah 31:9
And he shall pass over to his strong hold for fear, and his princes shall be afraid of the ensign, saith the LORD, whose fire is in Zion, and his furnace in Jerusalem. And he shall pass over to his strong hold for fear, and his princes shall be afraid of the ensign, saith the LORD, whose fire is in Zion, and his furnace in Jerusalem.
The chapter is a rebuke of Israel's rebellious turning to Egypt for help instead of trusting God. Trust in human strength is misplaced, for deliverance and power belong to God alone. The verse itself portrays God's defense and deliverance of Jerusalem, an intervention that strikes fear into its enemies.
It stands within Isaiah 28 to 33, prophecies concerning Israel that typify conditions in the Christian age. That larger section contains prophecies about the future, both near and far, repeatedly looking ahead to the coming and reign of Christ. Its imagery belongs to millennial times and is not a literal description of the final coming to judgment.
To turn from God to worldly civil power for help repeats Israel's unfaithfulness, a spiritual unfaithfulness, for God will not share His glory with another.