Nazarite

In the Hebrew Bible, a nazirite or nazarite is one who voluntarily took a vow described in Numbers 6:1–21. "Nazarite" comes from the Hebrew word נזיר nazir meaning "consecrated" or "separated". This vow required the person to:

After following these requirements for a designated interval (which would be specified in the individual's vow), the person would immerse in a mikveh and make three offerings: a lamb as a burnt offering (olah), a ewe as a sin-offering (hatat), and a ram as a peace offering (shelamim), in addition to a basket of unleavened bread, grain offerings and drink offerings, which accompanied the peace offering. They would also shave their head in the outer courtyard of the Jerusalem Temple and then place the hair on the same fire as the peace offering. (Numbers 6:18)

The nazirite is described as being "holy unto YHWH" (Numbers 6:8), yet at the same time must bring a sin offering. This has led to divergent approaches to the nazirite in the Talmud, and later authorities, with some viewing the nazirite as an ideal, and others viewing him as a sinner.

In Modern Hebrew the word "nazir" is commonly used for monks, both Christian and Buddhist – this meaning having largely displaced the original Biblical meaning.

Halakha (Jewish law) has a rich tradition on the laws of the nazirite. These laws were first recorded in the Mishna, and Talmud in tractate Nazir. They were later codified by Maimonides in the Mishneh Torah Hafla'ah, Nazir. From the perspective of Orthodox Judaism these laws are not a historical curiosity but can be practiced even today. However, since there is now no temple in Jerusalem to complete the vow, and any vow would be permanent, modern rabbinical authorities strongly discourage the practice to the point where it is almost unheard of today.

...
Wikipedia