וְיָֽדְעוּ֙ כָּל־יֹשְׁבֵ֣י מִצְרַ֔יִם כִּ֖י אֲנִ֣י יְהוָ֑ה יַ֧עַן הֱיוֹתָ֛ם מִשְׁעֶ֥נֶת קָנֶ֖ה לְבֵ֥ית יִשְׂרָאֵֽל׃
And all the inhabitants of Egypt shall know That I am the LORD, Because they have been a staff of reed To the house of Israel.
Read kabbalistic (mystical) interpretation of Ezekiel 29:6: and classical mystical sources.