וְהָיָ֤ה הֶחָסֹן֙ לִנְעֹ֔רֶת וּפֹעֲל֖וֹ לְנִיצ֑וֹץ וּבָעֲר֧וּ שְׁנֵיהֶ֛ם יַחְדָּ֖ו וְאֵ֥ין מְכַבֶּֽה׃ (ס)
And the strong shall be as tow, And his work as a spark; And they shall both burn together, And none shall quench them.
Read kabbalistic (mystical) interpretation of Isaiah 1:31: and classical mystical sources.