Metallurgy

He sends down from the sky, rain, and valleys flow according to their capacity, and the torrent carries a rising foam. And from that [ore] which they heat in the fire, desiring adornments and utensils, is a foam like it. Thus Allāh presents [the example of] truth and falsehood. As for the foam, it vanishes, [being] cast off; but as for that which benefits the people, it remains on the earth. Thus does Allāh present examples.

Bring me bars of iron" - until, when he had leveled [them] between the two mountain walls, he said, "Blow [with bellows]," until when he had made it [like] fire, he said, "Bring me, that I may pour over it molten copper."

So they [i.e., Gog and Magog] were unable to pass over it, nor were they able [to effect] in it any penetration.

He knows what penetrates into the earth and what emerges from it and what descends from the heaven and what ascends therein. And He is the Merciful, the Forgiving.

We have already sent Our messengers with clear evidences and sent down with them the Scripture and the balance that the people may maintain [their affairs] in justice. And We sent down iron, wherein is great military might and benefits for the people, and so that Allāh may make evident those who support Him and His messengers unseen. Indeed, Allāh is Powerful and Exalted in Might.