זֹ֥את תִּהְיֶ֖ה חַטַּ֣את מִצְרָ֑יִם וְחַטַּאת֙ כָּל־הַגּוֹיִ֔ם אֲשֶׁר֙ לֹ֣א יַֽעֲל֔וּ לָחֹ֖ג אֶת־חַ֥ג הַסֻּכּֽוֹת׃
This shall be the punishment of Egypt, and the punishment of all the nations that go not up to keep the feast of tabernacles.
Read midrashic interpretation of Zechariah 14:19: and classical rabbinic exegesis.