Numbers 18:4

And they shall be joined unto thee,.... As assistants in the sacred service:

and keep the charge of tabernacle of the congregation, for all the service of the tabernacle; Numbers 3:7 and

Numbers 3:8;

and a stranger shall not come nigh unto you; not any of the other tribes, only such as were of the tribe of Levi; they only were to be brought with them, and joined unto them, and assist them, and minister to them, as in Numbers 18:2; though the Jews h understand by a stranger anyone that was not a priest.

h Maimon. in Misn. Zebachim, c. 2. sect. 1.