וַיֹּ֥אמֶר לָהֶ֖ם שְׁמָע֣וּנִי הַלְוִיִּ֑ם עַתָּ֣ה הִֽתְקַדְּשׁ֗וּ וְקַדְּשׁוּ֙ אֶת־בֵּ֤ית יְהוָה֙ אֱלֹהֵ֣י אֲבֹתֵיכֶ֔ם וְהוֹצִ֥יאוּ אֶת־הַנִּדָּ֖ה מִן־הַקֹּֽדֶשׁ׃
and said unto them: ‘Hear me, ye Levites: now sanctify yourselves, and sanctify the house of the LORD, the God of your fathers, and carry forth the filthiness out of the holy place.
Read midrashic interpretation of II Chronicles 29:5: and classical rabbinic exegesis.