In the weekly Parsha, we read about the agreement of salt? What's the different agreement of salt or salt of agreement? whats the Kabbalistic meaning of salt in Judaism?

Salt symbolizes longevity, as meat or pickles which are salted, are preserved and don't spoil so fast (even before there was refrigeration), and salt itself can last indefinitely. Accordingly, "a covenant of salt" (18, 19; Chron. II, 13, 5) means an eternal covenant with the Kohanim and with the House of David.