He shall not make himself unclean for his father, or for his mother. The same injunction had been given to the priests (Le Numbers 21:12)—"for the crown of the anointing oil of his God is upon him." A similar reason restrained the Nazirite.
Because the consecration of his God is upon his head, i.e; because he wears the unshorn locks which are the outward sign of his separation unto God. The hair of the Nazirite was to him just what the diadem on the mitre was to the high priest, what the sacred chrism was to the sons of Aaron.
Both of these are called by the word nezer (Exodus 29:6; Le Exodus 21:12), from the same root as nazir. It was thought by some of the Jewish doctors that in these three particulars—the untouched growth of the hair, the abstinence from the fruit of the vine (cf.
Genesis 9:20), and the seclusion from the dead—the separated life of the Nazirite reproduced the unfallen life of man in paradise. This may have had some foundation in fact, but the true explanation of the three rules is rather to be found in the spiritual truth they teach in a simple and forcible way.