What does Joel 2:13 mean?

Don’t just tear your clothes—let your hearts break. Come back to the Lord your God, because he’s kind and full of compassion. He’s slow to get angry and quick to forgive. He might even change his mind about sending disaster. Joel 2:13 - Modern Text Bible

(God wants real change inside, not just outward signs of regret. He’s reminding them that he’s merciful and might hold back judgment if they truly return to him.)