Esias 45:2

2 I will go before thee, and will level mountains: I will break to pieces brazen doors, and burst iron bars.

Esias 45:2 In-Context

1 Thus saith the Lord God to my anointed Cyrus, whose right hand I have held, that nations might be obedient before him; and I will break through the strength of kings; I will open doors before him, and cities shall not be closed.
2 I will go before thee, and will level mountains: I will break to pieces brazen doors, and burst iron bars.
3 And I will give thee the treasures of darkness, I will open to thee hidden, unseen , that thou mayest know that I, the Lord thy God, that call thee by name, am the God of Israel.
4 For the sake of my servant Jacob, and Israel mine elect, I will call thee by thy name, and accept thee: but thou hast not known me.
5 For I am the Lord God, and there is no other God beside me; I strengthened thee, and thou hast not known me.

The Brenton translation of the Septuagint is in the public domain.