Shall iron break the northern iron and the steel? - Shall our weak forces be able to oppose and overcome the powers of the Chaldeans? נחשת nechasheth, which we here translate steel, property signifies brass or copper united with tin, which gives it much hardness, and enables it to bear a good edge.
The steel - “brass,” i. e., bronze. By the “iron” is meant Jeremiah‘s intercession; but this cannot alter the divine purpose to send Judah into exile, which is firm as steel and brass. For “brass” see Exodus 25:3 note. The alloy of copper and zinc now called brass was entirely unknown to the ancients.