The LORD will smite you: see verse 27.

Grievous boils: see verse 27.

From the sole of your foot to the crown of your head: that is, “all over you.” The boils will spread from knees and legs to the whole body, “from head to foot” (Good News Translation; similarly Contemporary English Version).

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .