זכריה, פרק ח׳, פסוק י״ח

Following a series of moral instructions, a long-awaited divine response finally arrives regarding a pressing question from the people: should they continue to observe their traditional days of fasting? The message transitions directly into God's clear answer to this inquiry [אבן עזרא]. This response, however, is strictly conditional on the people's actions and is deeply tied to the previous commands. If the Israelites faithfully carry out what God has asked of them, the fasts they asked about will be completely canceled. Rather than experiencing sorrow and deprivation, the people will celebrate with great joy on those very dates, overwhelmed by the abundant good that He will bring upon them [רד״ק].