יואל, פרק א׳, פסוק י״ג

When the daily spiritual service comes to a sudden halt, a profound crisis strikes the very heart of the nation's worship. The spiritual leaders, the priests, are called upon to respond with broken hearts and heavy mourning. They are instructed to put on sackcloth and enter the House of God, remaining there continuously. By keeping their garments of mourning on even through the night, they hope to awaken God's mercy [רד״ק].

The priests are addressed by two distinct descriptions, referring to them as ministers of the altar and ministers of God. The primary approach among commentators is that these descriptions are parallel, simply reflecting that serving at the altar is, in essence, serving God [רד״ק]. Alternatively, these titles address two entirely different groups of priests. The first group consists of those who performed the technical duties of the sacrifices without the proper inner devotion; they are left with nothing but despair and wailing. The second group represents the righteous priests who served God with a whole heart. It is this devoted group that is called to sleep in sackcloth, pray, and repent in order to overturn the harsh decree [מלבי״ם].

The underlying cause of this intense mourning is the complete cessation of the daily grain and drink offerings. With the daily sacrifices halted, the priests are left with no physical means to appease God [אבן עזרא].

A fundamental disagreement exists regarding what actually caused the offerings to stop. The widely accepted view explains that a devastating locust plague consumed all the crops, completely destroying the wheat and wine required for the daily service [מצודת דוד, מלבי״ם]. However, another perspective suggests that this event has nothing to do with locust damage. Instead, it is a prophecy foretelling the eventual destruction of the House of God and the permanent end of its service, serving as an eternal call for future generations to fast and mourn over the loss of the sanctuary [אברבנאל].