2 Chronicles 30:21
“And the children of Israel that were present at Jerusalem kept the feast of unleavened bread seven days with great gladness: and the Levites and the priests praised the Lord day by day, singing with loud instruments unto the Lord.”
That prepareth his heart to seek God, the Lord God of his fathers, though he be not cleansed according to the purification of the sanctuary.
And the Lord hearkened to Hezekiah, and healed the people.
And the children of Israel that were present at Jerusalem kept the feast of unleavened bread seven days with great gladness: and the Levites and the priests praised the Lord day by day, singing with loud instruments unto the Lord.
And Hezekiah spake comfortably unto all the Levites that taught the good knowledge of the Lord: and they did eat throughout the feast seven days, offering peace offerings, and making confession to the Lord God of their fathers.
And the whole assembly took counsel to keep other seven days: and they kept other seven days with gladness.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Related Verses
“And the children of Israel that were present kept the passover at that time, and the feast of unleavened bread seven days.”
“And there assembled at Jerusalem much people to keep the feast of unleavened bread in the second month, a very great congregation.”
“And all the congregation of Judah, with the priests and the Levites, and all the congregation that came out of Israel, and the strangers that came out of the land of Israel, and that dwelt in Judah, rejoiced.”
“Moreover Hezekiah the king and the princes commanded the Levites to sing praise unto the Lord with the words of David, and of Asaph the seer. And they sang praises with gladness, and they bowed their heads and worshipped.”
“And at the dedication of the wall of Jerusalem they sought the Levites out of all their places, to bring them to Jerusalem, to keep the dedication with gladness, both with thanksgivings, and with singing, with cymbals, psalteries, and with harps.”