4 The form הֲדוּרִים (hadurim) makes little, if any, sense here. It is probably a corruption of an original הָרָרִים (hararim, “mountains”), the reduplicated form of הָר (har, “mountain”).
5 That is, on the gates. Cf. “break the iron bars on bronze gates.”

In other versions

“I will go before you

and level the exalted places,

I will break in pieces the doors of bronze

and cut through the bars of iron,

I will go before you

and will level the mountains;

I will break down gates of bronze

and cut through bars of iron.

“I will go before you

and level the uneven places;

I will shatter the bronze doors

and cut the iron bars in two.

This is what the Lord says:

“I will go before you, Cyrus,

and level the mountains.

I will smash down gates of bronze

and cut through bars of iron.

“I myself will go before you,

and I will level the mountains.

I will break the doors of bronze

and cut through the bars of iron.

I will go before thee,

And make the crooked places straight:

I will break in pieces the gates of brass,

And cut in sunder the bars of iron:

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