A devastating national tragedy looms on the horizon, threatening to strike without a moment of warning. In the face of this impending doom, an urgent prophetic call demands an immediate and profound display of public mourning. The entire congregation of the nation is urged to wrap themselves in grief [מצודת ציון]. They are instructed to wear sackcloth, a thick and coarse fabric, and to cover themselves in ashes. While the primary approach among commentators understands this action as physically rolling in the ashes, another tradition suggests it means covering the head with them [רד״ק].
The required sadness is compared to the heartbreak of losing an only child. This represents a state of absolute mourning where no comfort can be found [רש״י, רד״ק, ביאור שטיינזלץ]. The people are told to raise a deeply bitter lamentation. The urgency of this grief stems from the nature of the coming threat. A cruel enemy and oppressor will attack so suddenly that there will be no time to prepare or even react when it happens [מצודת ציון]. Because of this, the weeping and mourning must begin right now, before the disaster actually strikes [רד״ק, ביאור שטיינזלץ].
Beyond the call to mourn, there is a profound expression of shared sorrow. The impending tragedy is not framed as something that will only happen to the nation. Instead, it is as if God Himself is declaring that the destruction will fall upon both Him and the people, revealing His complete partnership in their pain [רש״י].