Here "head" represents the Nazirite man's hair, which symbolizes his vow. AT: "defiles his long hair which shows everyone he is separated to God" or "he becomes defiled" (See: [[rc://en/ta/man/translate/figs-metonymy]])
# on the day of his purification
The abstract noun "purification" can be stated as the verbal phrase. AT: "on the day when he makes himself acceptable to God" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])