Num 6:1-2
The words, “if a man or woman make a separate vow, a Nazarite vow, to live consecrated to the Lord,” with which the law is introduced, show not only that the vow of the Nazarite was a matter of free choice, but that it was a mode of practising godliness and piety already customary among the people. Nazir, from נזר to separate, lit., the separated, is applied to the man who vowed that he would make a separation to (for) Jehovah, i.e., lead a separate life for the Lord and His service. The origin of this custom is involved in obscurity. There is no certain clue to indicate that it was derived from Egypt, for the so-called hair-offering vows are met with among several ancient tribes (see the proofs in Spencer, de legg. Hebr. rit. iv. 16, and Knobel in loc.), and have no special relationship to the Nazarite, whilst vows of abstinence were common to all the religions of antiquity. The Nazarite vow was taken at first for a particular time, at the close of which the separation terminated with release from the vow. This is the only form in which it is taken into consideration, or rules are laid down for it in the law before us. In after times, however, we find life-long Nazarites among the Israelites, e.g., Samson, Samuel, and John the Baptist, who were vowed or dedicated to the Lord by their parents even before they were born (Jdg 13:5, Jdg 13:14; 1Sa 1:11; Luk 1:15).