And he discovered the covering of Judah, and thou didst look in that day to the armour of the house of the forest.
He discovered the covering of Judah - the veil ( maacaak (H4539)) of Judah shall be taken off (Horsley); figurative, for exposing to shame as a captive (Isaiah 47:3; Nahum 3:5). Sennacherib dismantled all "the defensed cities of Judah" (Isaiah 36:1).
Thou didst look in that day. The prophetic preterite: so certain is what God foretells, as though it were already fulfilled.
To the armour of the house of the forest - the house of armoury, built of cedar from the forest of Lebanon by Solomon, on a slope of Zion called Ophel (1 Kings 7:2; 1 Kings 10:17; Nehemiah 3:19). Isaiah says (Isaiah 22:8-13) his countrymen look to their own strength to defend themselves, while others of them drown their sorrows as to their country in feasting, but none look to Yahweh.