כִּ֤י כַבֶּ֙גֶד֙ יֹאכְלֵ֣ם עָ֔שׁ וְכַצֶּ֖מֶר יֹאכְלֵ֣ם סָ֑ס וְצִדְקָתִי֙ לְעוֹלָ֣ם תִּֽהְיֶ֔ה וִישׁוּעָתִ֖י לְד֥וֹר דּוֹרִֽים׃ (ס)
For the moth shall eat them up like a garment, And the worm shall eat them like wool; But My favour shall be for ever, And My salvation unto all generations.
Read kabbalistic (mystical) interpretation of Isaiah 51:8: and classical mystical sources.