זכריה, פרק ח׳, פסוק י״ט

A question posed by the Babylonian exiles regarding the continuation of their traditional mourning practices is met with a divine promise of a historical transformation. The national days of grief are destined to become joyous festivals, provided the people correct their moral behavior. The primary approach among commentators is that the four fasts mentioned correspond to the months of the year and were established to mourn the destruction of Jerusalem and the Temple [רש"י, מצודת דוד, רד"ק, ביאור שטיינזלץ]. The fast of the fourth month marks the breach of the city walls, the fifth month mourns the destruction of the Temple itself, the seventh month is the Fast of Gedaliah, and the tenth month commemorates the beginning of the siege on Jerusalem. This message is directed specifically to the House of Judah, as they were the ones directly struck by these disasters and who mourned on these days, unlike the Ten Tribes who did not return to the land [מצודת דוד, רד"ק].

While the fasts are tied to specific months, the exact dates underwent historical adjustments. For example, the fast in the fourth month was set on the seventeenth day because of five separate tragedies that occurred on that date, and there are traditional discussions regarding the precise day Gedaliah was murdered [אבן עזרא]. Addressing the people's core question of whether they must continue to fast, the prophet brings glad tidings. He reveals that in the days of redemption, these periods of mourning will not merely be canceled, but will actively turn into times of light, celebration, and joy [מלבי"ם, ביאור שטיינזלץ].

However, this complete redemption and the end of the fasts are entirely dependent on a clear moral condition: the people must repent and embrace a genuine love for truth and peace [מצודת דוד, מלבי"ם, רד"ק]. The prophet delivers a sharp message to those inquiring about the fasts. He points out that it would have been far better for the people to strictly observe God's original commandments concerning truth and justice, rather than merely focusing on the fast days that their ancestors voluntarily took upon themselves [אבן עזרא].

By their very nature, days of fasting serve to unite the public and encourage social repair. Because of this, the prophet issues a warning for the future. Even when the days of mourning are finally transformed into joyous holidays, it remains an absolute duty for the people to hold fast to the values of truth and peace in their relationships with one another, rather than sinking into thoughtless revelry [ביאור שטיינזלץ].