The Levites were more upright etc - See the marginal reference. Urijah, the high priest, had participated to some extent in the impieties of Ahaz 2 Kings 16:10-16. He and many of the priests may, therefore, have looked coldly on the reforming zeal of Hezekiah.
Related Commentaries of 2 Chronicles 29:34
2 Chronicles 29:34
34 But the priests were too few, so that they could not flay all the burnt offerings: wherefore their brethren the Levites did helph them, till the work was ended, and until the other priests had sanctified themselves: for the Levites were more upright in heart to sanctify themselves than the priests.