2 Chronicles 30:21-23

21The Israelites who were present in Jerusalem celebrated the Festival of Unleavened Bread for seven days with great rejoicing, while the Levites and priests praised the Lord every day with resounding instruments dedicated to the Lord. 22Hezekiah spoke encouragingly to all the Levites, who showed good understanding of the service of the Lord. For the seven days they ate their assigned portion and offered fellowship offerings and praised the Lord, the God of their ancestors. 23The whole assembly then agreed to celebrate the festival seven more days; so for another seven days they celebrated joyfully.