וּמֵהֶ֖ם עַל־כְּלֵ֣י הָעֲבוֹדָ֑ה כִּֽי־בְמִסְפָּ֣ר יְבִיא֔וּם וּבְמִסְפָּ֖ר יוֹצִיאֽוּם׃
And certain of them had charge of the vessels of service; for by tale were they brought in and by tale were they taken out.
Read midrashic interpretation of I Chronicles 9:28: and classical rabbinic exegesis.