'Pillar' in the Bible

"As for me, today I'm making you a fortified city, an iron pillar, and a bronze wall against the whole land against the kings of Judah, against its princes, against its priests, and against the people of the land.

On each pillar was a capital of bronze, and the height of each capital was five cubits. Latticework and pomegranates, all of bronze, were all around the capital. And the second pillar was like this, including the pomegranates.