"Bring me blocks of iron."(2441) At length, when he had filled up the space between the two steep mountain-sides, He said, "Blow (with your bellows)" Then, when he had made(2442) it (red) as fire, he said: "Bring me, that I may pour over it, molten lead."
2441 I understand the defences erected to have been a strong barrier of iron, with iron Gates. The jambs of the Gates were constructed with blocks or bricks of iron, and the interstices filled up with molten lead, so as to form an impregnable mass of metal. It may be that there was a stone wall also, but that is not mentioned. There was none in the Iron Gate near Bukhara ; see Appendix VI at the end of his Surah. 2442 Made it (red) as fire, what does "it" refer to? Probably to the iron, either in sheets or blocks, to be welded with molten lead.