The Nazir has an important role in this week’s sidra. A person who opted to be a Nazir had to follow an ascetic lifestyle – no drinking wine, no contact with the dead, no cutting of his hair: “He shall let the hair of his head grow long” (Num. 6:5).
Hair figures in a number of religious contexts and in modern times the way a person’s hair is covered is a major mark of their religiosity, hence all the halachic debates about the size and style of a man’s kippah and the status of a woman’s headscarf or sheitel.
Another hair problem is the subject of the Yiddish saying, “The first grey hair is a summons from the angel of death”.
Since hair can be an indication of vanity, covering it indicates modesty. But letting the Nazirite’s hair grow unchecked? Perhaps it is because unruly hair looks a mess and denotes a person who denies him- or herself the socially admired methods of bodily indulgence.