Joel 3:16

The Lord also shall roar... — This is the key-note of the prophecy of Amos, who opens his appeal with these words. The majestic roar of the lion is transferred to express victorious utterance of the Lord’s judgment: it is irresistible. As St. Paul wrote, “The Lord Himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God” (1 Thessalonians 2:16). The temporal success of the Jews in their future conflict with their enemies is blended with the final triumph of the Lord in the judgment day.