כִּ֤י כַבֶּ֙גֶד֙ יֹאכְלֵ֣ם עָ֔שׁ וְכַצֶּ֖מֶר יֹאכְלֵ֣ם סָ֑ס וְצִדְקָתִי֙ לְעוֹלָ֣ם תִּֽהְיֶ֔ה וִישׁוּעָתִ֖י לְד֥וֹר דּוֹרִֽים׃ (ס)
Porque como á vestidura los comerá polilla, como á lana los comerá gusano; mas mi justicia permanecerá perpetuamente, y mi salud por siglos de siglos.
Ibn Ezra on Isaiah
סס The worm. It is hap. leg. But my righteousness shall be for ever. Comp. And His righteousness endureth for ever (Ps. 112:8).8I. E. comparing this phrase with a similar one (Ps. 112:3) explains the verb היה by the verb עמד, which more exclusively expresses duration, while היה has also the meaning to become, signifying a single act.