2 Chronicles 30:15 (KJV)

And there assembled at Jerusalem much people to keep the feast of unleavened bread in the second month, a very great congregation.

And they arose and took away the altars that were in Jerusalem, and all the altars for incense took they away, and cast them into the brook Kidron.

Then they killed the passover on the fourteenth day of the second month: and the priests and the Levites were ashamed, and sanctified themselves, and brought in the burnt offerings into the house of the Lord.

And they stood in their place after their manner, according to the law of Moses the man of God: the priests sprinkled the blood, which they received of the hand of the Levites.

For there were many in the congregation that were not sanctified: therefore the Levites had the charge of the killing of the passovers for every one that was not clean, to sanctify them unto the Lord.