Numbers 6:5

5.There shall no razor come upon his head. It cannot be certainly determined why God would have the Nazarites let their hair grow, except that by this present mark of their consecration, they might be more and more reminded of their vow. Some think that it was a mark of honor, as if they wore a crown on their heads. In this the Popish clergy are more than ridiculous, comparing themselves to the Nazarites by their circular tonsure. (334) But this reason satisfies myself, that God would constantly exercise them in the faithful performance of their vow by this visible sign. It is a mark of manhood to cut the hair, and this, as Paul says, a natural feeling dictates. ( 1 Corinthians 11:14.) Therefore, the dedication of the Nazarites was shewn conspicuously by their heads, lest they should fail in their own vows through carelessness or forgetfulness. A question arises respecting the women, for whom this command appears superfluous; but this is easily answered, that they were thus bound to let their hair grow, so as to have it long not only from custom, but in accordance with their vow. Yet there will be nothing absurd in the synecdoche, whereby that is spoken of both the sexes which applies only to the males. Here also the devil formerly played his game, when he persuaded certain monks, as Augustine relates, (335) to make a shew of sanctity by wearing long hair; for, in order that the celibacy which they had vowed might be more conspicuous, they would not allow themselves to be men, having “made themselves eunuchs for the kingdom of heaven’s sake;” ( Matthew 19:12;) and, therefore, their long hair was a sign of their virginity. This example teaches us to beware of the wiles of Satan, lest our κακοζηλία make us rather the apes than the imitators of the ancients.