Isaiah continues to describe a time in the future when an army will attack the people of Jerusalem. Past tense verbs can be translated with future tense verbs. (See: [[rc://en/ta/man/translate/figs-pastforfuture]])
The abstract noun "protection" can be stated as a verb. Alternate translation: "Yahweh will take away everything that has protected the people of Judah" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
Here the phrase "to look to" means to trust in something. Alternate translation: "to defend yourselves you will get the weapons" (See: [[rc://en/ta/man/translate/figs-idiom]])