One who consecrates himself to God by vowing to abstain from wine, grapes and grape derivatives, from cutting his hair, and from defiling himself through contact with a dead person or animal carcass (Num. 6:2–8). Such a commitment without a specified time limit expires automatically after 30 days; however, it is possible for the commitment to last a lifetime. At the end of the specified period, a Nazirite offers a series of sacrifices, shaves his head, and burns his hair in the Nazirites' Chamber near the Temple. If a Nazirite accidentally becomes impure, he shaves his head, offers sacrifices, and begins his term anew – after undergoing the normal procedure for ritual purification (see Immersion, Ritual).
The relevant laws are detailed in Nazir, the fourth tractate of the Order Nashim in the Mishnah. Nazir consists of nine chapters, in both the Babylonian and Jerusalem Talmuds.
Nazirites mentioned in the Bible include Samson (Judg. 13:7) and, according to some interpretations, Samuel (I Sam. 1:11). The Essenes of the late Second Temple period adopted the practices of the Nazirites while observing further restrictions. Though in principle the talmudic sages praised the Nazirite for wishing to distance himself from sin, they strongly discouraged the practice (to the extent that some viewed it as sinful). With the destruction of the Temple, which brought an end to the sacrificial service, Nazirite laws as laid down in the Torah ceased. Nevertheless, there remained certain individuals who continued the traditions of the Nazirites (primarily the abstinence from wine). Saadiah Gaon, Judah Halevi and Maimonides all opposed the practice, viewing it as foreign to Judaism, which teaches Jews to sanctify themselves in the realm of permissible human activities and refrain only from that which is expressly forbidden.