ישעיהו, פרק נ״א, פסוק ח׳

A sharp contrast exists between the fragile, temporary existence of the enemies of the Israelites and the eternal nature of God's promise. The downfall of the wicked is illustrated through imagery drawn from the world of textiles, specifically moths and insects that feed on and destroy fabrics [רש״י, מצודת ציון, אבן עזרא]. This metaphor reveals that these enemies do not pose a true threat. Just as a piece of clothing might appear perfectly whole from a distance but is revealed to be moth-eaten and entirely useless upon closer inspection, the wicked will ultimately vanish from the earth as evil consumes them [רד״ק, ביאור שטיינזלץ].

The imagery of insects eating both finished garments and raw wool is viewed by some commentators as a poetic repetition meant to emphasize the certainty of this destruction [מצודת דוד]. However, others identify a profound distinction between the two materials. In this view, the insect consuming the finished garment symbolizes the punishment awaiting those who insult the Israelites. The insect consuming the raw wool, on the other hand, represents a far more severe penalty for those who blaspheme the Torah. Because wool is the raw material from which a garment is made, its destruction signifies an earlier, absolute, and utterly devastating punishment. It crumbles the enemy before they even have the chance to fully form or organize into a finished threat [מלבי״ם].

In stark contrast to the total destruction of these enemies stands the enduring promise made to the Israelites. God's righteousness and salvation are destined to last forever [מצודת דוד, רד״ק], provided that sin does not cause these blessings to cease [שד״ל].

The promise employs two distinct concepts of time to describe this eternity, revealing a deep distinction between the source of the blessing and the people receiving it. One concept denotes a continuous, unchanging, and infinite stretch of time. This is paired with God's righteousness, as righteousness is rooted in His very essence, which is entirely independent of time and never changes. The second concept describes time as divided into distinct periods or generations. This is paired with God's salvation because salvation is experienced by human beings. Since humans are bound by the limits of time, the salvation they receive unfolds, adapts, and renews itself to meet the changing realities of each new generation [מלבי״ם].