דברי הימים ב, פרק כ״ג, פסוק י״ח

After the rule of Athaliah, a time when Baal worship spread widely, the daily offerings had been stopped and the holiness of the Temple was left neglected. To repair this damage, Jehoiada takes action to renew the proper order of service in the House of God [מצודת דוד, מלבי״ם, ביאור שטיינזלץ]. He assigns specific roles and appoints officials to oversee the sacred duties [רש״י, מצודת ציון, רלב״ג]. Carefully following past traditions, Jehoiada places the priests and Levites as heads of the various divisions and watches, reinstating the exact structure originally established by King David [רלב״ג, ביאור שטיינזלץ].

The main goal of appointing these leaders is to ensure that the sacrifices are offered at their correct times, fulfilling the laws written in the Torah of Moses [מצודת דוד, ביאור שטיינזלץ]. This renewed service is brought back to life with great joy. As the offerings are made, the rituals are accompanied by music, specifically using the songs that King David originally composed and set in place for the Temple [מצודת דוד].