Adam Clarke on 1 Kings 4:13

Threescore great cities with walls and brazen bars - These were fortified cities: their gates and bars covered with plates of brass. Such were the gates in Priam's palace: -

Ipse inter primos correpta dura bipenni

Limina perrumpit, Postes que a cardine vellit

Aeratos. Virg. Aen., lib. ii. ver. 479.

Fierce Pyrrhus in the front, with forceful sway,

Plied the huge axe, and hew'd the beams away;

The solid timbers from the portal tore,

And rent from every hinge the Brazen door.

Pitt.