וְיָדְעוּ֙ הָעָ֣ם כֻּלּ֔וֹ אֶפְרַ֖יִם וְיוֹשֵׁ֣ב שֹׁמְר֑וֹן בְּגַאֲוָ֛ה וּבְגֹ֥דֶל לֵבָ֖ב לֵאמֹֽר׃
And all the people shall know, even Ephraim and the inhabitant of Samaria, that say in pride and in arrogancy of heart:
Read kabbalistic (mystical) interpretation of Isaiah 9:8: and classical mystical sources.