'Bars' in the Bible

Thus says Yahweh to me: Make bonds and bars, and put them on your neck;

Go, and tell Hananiah, saying, Thus says Yahweh: You have broken the bars of wood; but you have made in their place bars of iron.

Arise, go up to a nation that is at ease, that dwells without care, says Yahweh; that have neither gates nor bars, that dwell alone.

The mighty men of Babylon have forborne to fight, they remain in their strongholds; their might has failed; they are become as women: her dwelling places are set on fire; her bars are broken.