Jeremiah 1:18

a defenced city, and an iron pillar; and brasen walls Jeremiah was to be fortified by divine strength against the attacks which he would have to confront throughout his prophetic life. The assaults would be severe, and hence the force of the figures under which he is described. Jeremiah would need a pre-eminent degree of strength. Cp. Ezekiel 3:9. The words "and an iron pillar" are probably to be omitted (with LXX), as inconsistent with the idea of a siege. If we retain them, we may explain the sentence as expressing in the strongest manner what is impregnable and cannot be overthrown.

against the kings of judah Josiah, Jehoahaz, Jehoiakim, Jehoiachin, Zedekiah.