2 Chronicles 29:15-17

15And they gathered their brethren, and hallowed themselves, and came, according to the commandment of the king by the words of Jehovah, to cleanse the house of Jehovah.

16And the priests went into the inner part of the house of Jehovah to cleanse it, and carried forth all the uncleanness that they found in the temple of Jehovah, into the court of the house of Jehovah. And the Levites took it to carry it forth into the brook Kidron.

17And they began on the first of the first month to hallow, and on the eighth day of the month they came to the porch of Jehovah; and they hallowed the house of Jehovah eight days; and on the sixteenth day of the first month they made an end.