2 Chronicles 30:15-17

15They slaughtered the Passover lamb on the fourteenth day of the second month. The priests and the Levites were ashamed and consecrated themselves and brought burnt offerings to the temple of the Lord.

16Then they took up their regular positions as prescribed in the Law of Moses the man of God. The priests splashed against the altar the blood handed to them by the Levites.

17Since many in the crowd had not consecrated themselves, the Levites had to kill the Passover lambs for all those who were not ceremonially clean and could not consecrate their lambs to the Lord.