Jeremiah 1:18 KJV
For, behold, I have made thee this day a defenced city, and an iron pillar, and brasen walls against the whole land, against the kings of Judah, against the princes thereof, against the priests thereof, and against the people of the land.
Jeremiah 1:15–19 KJV Chapter Context
15
For, lo, I will call all the families of the kingdoms of the north, saith the LORD; and they shall come, and they shall set every one his throne at the entering of the gates of Jerusalem, and against all the walls thereof round about, and against all the cities of Judah.
16
And I will utter my judgments against them touching all their wickedness, who have forsaken me, and have burned incense unto other gods, and worshipped the works of their own hands.
17
Thou therefore gird up thy loins, and arise, and speak unto them all that I command thee: be not dismayed at their faces, lest I confound thee before them.
18
For, behold, I have made thee this day a defenced city, and an iron pillar, and brasen walls against the whole land, against the kings of Judah, against the princes thereof, against the priests thereof, and against the people of the land.
19
And they shall fight against thee; but they shall not prevail against thee; for I am with thee, saith the LORD, to deliver thee.