Numbers 18:19

18:19 All the raised offerings of the holy things that the Israelites offer to the Lord, I have given to you, and to your sons and daughters with you, as a perpetual ordinance. It is a covenant of salt ¹  forever before the Lord for you and for your descendants with you.”

Numbers 18:2

18:2 “Bring with you your brothers, the tribe of Levi, the tribe of your father, so that they may join ²  with you and minister to you while ³  you and your sons with you are before the tent of the testimony.

Numbers 13:5

13:5 from the tribe of Simeon, Shaphat son of Hori;

[18:19]  ¹ sn Salt was used in all the offerings; its importance as a preservative made it a natural symbol for the covenant which was established by sacrifice. Even general agreements were attested by sacrifice, and the phrase “covenant of salt” speaks of such agreements as binding and irrevocable. Note the expression in Ezra 4:14, “we have been salted with the salt of the palace.” See further J. F. Ross, IDB 4:167.

[18:2]  ² sn The verb forms a wordplay on the name Levi, and makes an allusion to the naming of the tribe Levi by Leah in the book of Genesis. There Leah hoped that with the birth of Levi her husband would be attached to her. Here, with the selection of the tribe to serve in the sanctuary, there is the wordplay again showing that the Levites will be attached to Aaron and the priests. The verb is יִלָּווּ (yillavu), which forms a nice wordplay with Levi (לֵוִי). The tribe will now be attached to the sanctuary. The verb is the imperfect with a vav (ו) that shows volitive sequence after the imperative, here indicating a purpose clause.

[18:2]  ³ tn The clause is a circumstantial clause because the disjunctive vav (ו) is on a nonverb to start the clause.