Parashas Bamidbar · Side page (no TT primary unit)
אַ֣ךְ אֶת־מַטֵּ֤ה לֵוִי֙ לֹ֣א תִפְקֹ֔ד וְאֶת־רֹאשָׁ֖ם לֹ֣א תִשָּׂ֑א בְּת֖וֹךְ בְּנֵ֥י יִשְׂרָאֵֽל׃
Do not on any account enroll the tribe of Levi or take a census of them with the Israelites.
Bamidbar Rabbah 1:12 — EXTRA.
אך את מטה לוי לא תפקד —\ldots לפי שהם ממונים על המשכן.
English: “Only the tribe of Levi you shall not count” — \ldots because they are appointed over the Mishkan.
Custom
Chazal explain the exclusion of Levi as protecting their exclusive dedication to the Mishkan.