2 Chronicles 30:1-3, 13-20

Hezekiah sent word to all Israel and to Judah and also wrote letters to Ephraim and Manasseh to come to the house of the LORD at Jerusalem to celebrate the Passover Feast to the LORD God of Israel. For the king and his officials and all the assembly in Jerusalem had decided to celebrate the Passover in the second month, [Num 9:10, 11] since they could not celebrate it at that time because a sufficient number of priests had not consecrated themselves, nor had the people assembled at Jerusalem.

Now many people were gathered at Jerusalem to celebrate the Feast of Unleavened Bread in the second month; it was a very large assembly. They took action and removed the [pagan] altars which were in Jerusalem; they also removed all the incense altars and threw them into the Brook Kidron [the dumping place for the ashes of such repulsive things]. Then they slaughtered the Passover lambs on the fourteenth day of the second month. And the priests and the Levites were ashamed of themselves, and consecrated themselves and brought burnt offerings to the house of the LORD. They stood at their accustomed stations, in accordance with the Law of Moses, the man of God. The priests sprinkled the blood [which they received] from the hand of the Levites [on the altar]. For there were many in the assembly who had not consecrated themselves [that is, become ceremonially clean and free from all sin]; so the Levites had to slaughter the Passover lambs for everyone who was not clean, in order to make them holy for the LORD. For the majority of the people, many from Ephraim and Manasseh, Issachar and Zebulun, had not purified themselves, and yet they ate the Passover contrary to what had been prescribed. For Hezekiah had prayed for them, saying, “May the good LORD pardon everyone who sets his heart to seek God—the LORD God of his fathers—even though it is not in accordance with the [ceremonial] purification [rules] of the sanctuary.” So the LORD listened to Hezekiah and healed the people [of their uncleanness].