יַכְּכָ֨ה יְהוָ֜ה בִּשְׁחִ֣ין רָ֗ע עַל־הַבִּרְכַּ֙יִם֙ וְעַל־הַשֹּׁקַ֔יִם אֲשֶׁ֥ר לֹא־תוּכַ֖ל לְהֵרָפֵ֑א מִכַּ֥ף רַגְלְךָ֖ וְעַ֥ד קָדְקֳדֶֽךָ׃
The LORD will smite thee in the knees, and in the legs, with a sore boil, whereof thou canst not be healed, from the sole of thy foot unto the crown of thy head.
Read midrashic interpretation of Deuteronomy 28:35: and classical rabbinic exegesis.