נָשֹׂ֗א אֶת־רֹאשׁ֙ בְּנֵ֣י קְהָ֔ת מִתּ֖וֹךְ בְּנֵ֣י לֵוִ֑י לְמִשְׁפְּחֹתָ֖ם לְבֵ֥ית אֲבֹתָֽם׃
’Take the sum of the sons of Kohath from among the sons of Levi, by their families, by their fathers’houses,
Read kabbalistic (mystical) interpretation of Numbers 4:2: and classical mystical sources.