A – Salvation
Chapter 4 concludes the unit focused on the Day of the Lord (Chapters 2–4). Notice the opening phrase, “On that day” (here in 4:2), which recurs throughout Chapters 2–4. In Chapters 2–3, the Day of the Lord is depicted as a harsh and fearsome event, filled with vivid imagery of human humiliation before the fearsome majesty of God. Chapter 4, however, shifts to a different tone, offering an optimistic conclusion to the Day of the Lord: the salvation that will come to Jerusalem.

A few central ideas characterize this salvation:
1. Salvation for the Remnant of Israel: Following a process of purging impurities, only the righteous and innocent will remain in Jerusalem, and they will be the ones to experience salvation: “All in Jerusalem who are inscribed to live” (4:3).
2. These righteous individuals will be crowned with glory and majesty (4:2), though this will not be human pride but glory derived from the Lord’s name (“the Lord’s shoot”).
3. Jerusalem will become a protected zone, symbolized by a canopy and cloud, representing two ideas:
* Miraculous protection: “A covering, a hiding place from the deluge, from the rain” (4:6).
* The divine presence residing in Jerusalem: “For over all the glory a canopy shields” (4:5).

The theme of salvation centered in Jerusalem, as a refuge from dangers (“shade all day from searing heat and a covering, a hiding place from the deluge, from the rain”; v. 6) and as a gathering place for the righteous after the Day of the Lord descends upon the world, will reappear throughout the Book of Yeshayahu in various contexts. This vision connects back to what we saw in Chapters 1–2 — the disappointment in the city that was meant to be a beacon of justice and righteousness, and the vision of Jerusalem restored as a center for proclaiming the word of the Lord to all nations. The climax of the Day of the Lord is the restoration of Jerusalem to its spiritual glory and the fulfillment of its intended role. As the book progresses, we will trace the development of this idea.

B – Verse 4
Some have pointed out that Verse 4 seems out of place in the chapter’s flow. Amid the verses describing salvation, there is a mention of the divine punishment necessary to cleanse the city of its wickedness: “… after the Lord has cleaned the filth from the women of Zion, washed away Jerusalem's staining blood with a spirit of judgment, a spirit that burns.” Perhaps the placement of this verse can be understood in light of parallels to similar prophecies. A comparison with Ovadya 1 and Yoel 2–3 reveals a picture very similar to our chapter: “There will be a remnant on Mount Zion” (Ovadya 1:17; Yoel 3:5). However, there is one notable difference: in Yoel and Ovadya, the remnant in Jerusalem is saved from the nations, who suffer the divine punishment. In contrast, the Day of the Lord as described here brings divine punishment within Jerusalem itself, upon the inhabitants of Yehuda, with only a portion of them (the righteous) surviving to witness salvation. This is precisely the message sharpened by Verse 4 in the heart of the salvation narrative: the salvation described here is not the classic type of deliverance for Israel from the nations but a salvation achieved through purging the wickedness found within Jerusalem itself.

C – Articles
Here are two recommended articles:
1. Yehuda Eisenberg highlights parallels between the Exodus and the salvation described in our chapter.
2. Rav Avia Hacohen discusses the structure of Chapters 1–4 and points out connections between their structure and the layout of passages in Sefer Devarim.