2 Chronicles 29:34

But the priests were too few, so that they could not flay all the burnt offerings, a task which they were supposed to perform themselves; wherefore their brethren, the Levites, did help them, it being a case of unavoidable necessity, of an emergency, till the work was ended, and until the other priests, those who came in from the outlying cities, had sanctified themselves; for the Levites were more upright in heart to sanctify themselves than the priests, they displayed greater alacrity than the priests, probably because the latter had become more deeply involved in idolatry under Ahaz.