וְהָ֥יָה צֶ֖דֶק אֵז֣וֹר מָתְנָ֑יו וְהָאֱמוּנָ֖ה אֵז֥וֹר חֲלָצָֽיו׃
And righteousness shall be the girdle of his loins, And faithfulness the girdle of his reins.
Read kabbalistic (mystical) interpretation of Isaiah 11:5: and classical mystical sources.