וְכָל־קָרְבַּ֣ן מִנְחָתְךָ֮ בַּמֶּ֣לַח תִּמְלָח֒ וְלֹ֣א תַשְׁבִּ֗ית מֶ֚לַח בְּרִ֣ית אֱלֹהֶ֔יךָ מֵעַ֖ל מִנְחָתֶ֑ךָ עַ֥ל כָּל־קָרְבָּנְךָ֖ תַּקְרִ֥יב מֶֽלַח׃ (ס)
And every meal-offering of thine shalt thou season with salt; neither shalt thou suffer the salt of the covenant of thy God to be lacking from thy meal-offering; with all thy offerings thou shalt offer salt.
Read kabbalistic (mystical) interpretation of Leviticus 2:13: and classical mystical sources.