Jeremiah 15:12 - Joseph Benson’s Commentary on the Old and New Testaments

Shall iron break the northern iron? The northern iron is the hardest of any. “It is here,” says Blaney, “justly supposed to denote, in a primary sense, that species of hardened iron, or steel, called in Greek χαλυψ, from the Chalybes, a people bordering on the Euxine sea, and consequently lying to the north of Judea, by whom the art of tempering steel is said to have been discovered. Strabo speaks of this people as known in former times by the name of Chalybes, but afterward called Chaldæi, and mentions their iron mines, lib. 12. p. 549. These, however, were a different people from the Chaldeans who were united with the Babylonians.” “The words, if applied to Jeremiah, import thus much, that, as common iron cannot contend for hardness with the northern iron, or with steel, so the opposition which the Jews made against him should be easily vanquished and disappointed, because the Lord was with him to save him, Jeremiah 15:20. If the words relate to the Jews, as the following verses plainly do, the sense is, that the Chaldeans coming from the north would be as much too hard for them to engage with, as the northern iron was superior in strength to the common metal of that kind.” Lowth. But perhaps the expression is not merely metaphorical: it is not unlikely that the Babylonians had their armour from the Chalybes, and that therefore it was made of iron much harder, and of much better proof, than that of which the armour of the Jews was formed.