Isaiah 45:2 Kabbalah

אֲנִי֙ לְפָנֶ֣יךָ אֵלֵ֔ךְ וַהֲדוּרִ֖ים אושר [אֲיַשֵּׁ֑ר] דַּלְת֤וֹת נְחוּשָׁה֙ אֲשַׁבֵּ֔ר וּבְרִיחֵ֥י בַרְזֶ֖ל אֲגַדֵּֽעַ׃

I will go before thee, and make the crooked places straight; I will break in pieces the doors of brass, and cut in sunder the bars of iron;

Read kabbalistic (mystical) interpretation of Isaiah 45:2: and classical mystical sources.