וְלִבְנֵ֥י קְהָ֖ת לֹ֣א נָתָ֑ן כִּֽי־עֲבֹדַ֤ת הַקֹּ֙דֶשׁ֙ עֲלֵהֶ֔ם בַּכָּתֵ֖ף יִשָּֽׂאוּ׃
But unto the sons of Kohath he gave none, because the service of the holy things belonged unto them: they bore them upon their shoulders.
Read kabbalistic (mystical) interpretation of Numbers 7:9: and classical mystical sources.