Talmud References for I Chronicles 23:28

כִּ֣י מַעֲמָדָ֞ם לְיַד־בְּנֵ֣י אַהֲרֹ֗ן לַעֲבֹדַת֙ בֵּ֣ית יְהוָ֔ה עַל־הַחֲצֵרוֹת֙ וְעַל־הַלְּשָׁכ֔וֹת וְעַֽל־טָהֳרַ֖ת לְכָל־קֹ֑דֶשׁ וּמַֽעֲשֵׂ֔ה עֲבֹדַ֖ת בֵּ֥ית הָאֱלֹהִֽים׃

For their station was at the side of the sons of Aaron for the service of the house of the LORD, in the courts, and in the chambers, and in the purifying of all holy things, even the work of the service of the house of God;