Kulo is the little word for the whole of a thing: kol, all, wearing a personal suffix. All of him. And in the grammar of purity it is the word that decides whether anything happened at all: the Torah requires the one immersing to wash "all his flesh" in the water (Leviticus 15:16), and the halakhah drew the line hard, one part held out and it is no immersion. The mikvah does not do percentages.

English gives "all" and "whole," which is accurate and weightless, and the KJV, ESV, NASB, and NIV cannot be blamed for it. What the English reader misses is where the Torah spends the word most strangely.

Because the strangest verse in the purity laws turns on it: the leper whose plague has covered kulo, all of him, "he is tahor" (Leviticus 13:13). Half-covered, unclean; wholly covered, clean. The system is telling you something it never says out loud: totality is the turning point. What is wholly given over can be wholly made new, and what you hold above the surface is the only part the water cannot touch. The bride says it the other way, in joy: kulo machamadim, "he is altogether lovely" (Song of Songs 5:16). All of him. That is the measure.