What does 2 Chronicles 29:5 mean?

and said, 'Listen to me, Levites! Set yourselves apart for God now, and set apart the temple of the Lord, the God of your ancestors. Remove everything unclean from the holy place.' 2 Chronicles 29:5 - Modern Text Bible

(Hezekiah tells the Levites to purify themselves and the temple, clearing out anything that doesn’t belong. He’s serious about restoring true worship.)