A covenant of salt - Compare the marginal reference. covenants were ordinarily cemented in the East by the rites of hospitality; of which salt was the obvious token, entering as it does into every article of diet. It indicates perpetuity: compare Leviticus 2:13 note.
Related Commentaries of Numbers 18:19
Numbers 18:19
19 All the heave offerings of the holy things, which the children of Israel offer unto the LORD, have I given thee, and thy sons and thy daughters with thee, by a statute for ever: it is a covenant of salt for ever before the LORD unto thee and to thy seed with thee.