דברי הימים ב, פרק כ׳, פסוק כ״ז

The journey home following a great victory is characterized by united leadership and a deep feeling of gratitude. The people of Judah and Jerusalem returned to their places together [ביאור שטיינזלץ].

Their decision to go back to Jerusalem with joy was not a passing emotion. It was a firm resolve to return with open happiness, a feeling that would later be expressed through playing music [מלבי״ם]. This great joy stemmed directly from the help and salvation God granted them against their enemies [מצודת דוד].

Beyond the rescue itself, the people reached a deep realization. They understood that the very arrival of their enemies to wage war was orchestrated by God from the beginning. He brought this conflict upon them entirely to bring them joy in the end through His great salvation [מלבי״ם].