וְנוֹדַ֤ע יְהוָה֙ לְמִצְרַ֔יִם וְיָדְע֥וּ מִצְרַ֛יִם אֶת־יְהוָ֖ה בַּיּ֣וֹם הַה֑וּא וְעָֽבְדוּ֙ זֶ֣בַח וּמִנְחָ֔ה וְנָדְרוּ־נֵ֥דֶר לַֽיהוָ֖ה וְשִׁלֵּֽמוּ׃
And the LORD shall make Himself known to Egypt, and the Egyptians shall know the LORD in that day; yea, they shall worship with sacrifice and offering, and shall vow a vow unto the LORD, and shall perform it.
Read midrashic interpretation of Isaiah 19:21: and classical rabbinic exegesis.