2. crooked … straight—(Isa 40:4), rather, "maketh mountains plain" [Lowth], that is, clear out of thy way all opposing persons and things. The Keri reads as in Isa 45:13, "make straight" (Margin).
gates of brass—(Ps 107:16). Herodotus (1.179) says, Babylon had a hundred massive gates, twenty-five on each of the four sides of the city, all, as well as their posts, of brass.
bars of iron—with which the gates were fastened.