A quick word search on “Nazirite[s]” show only the following:
Num 6:2-21 – used at least 10 times
Judges 13:5,7 and 16:17 (Samson)
This made me wonder if Numbers 6 was created primarily to explain Judges 13. I find it odd that it’s not mentioned more.
Even Numbers 6:2 implies familiarity with this vow “If anyone, man or woman, explicitly utters a nazirite’s vow…” then it goes on to explain what they shall and shall not do. But it begins with the assumption that everybody knows what a nazirite vow is. It doesn’t say that a person should take this vow, or even why a person should take this vow, it just assumes that some people do, and then there are rules to be followed. JSB footnote in Numbers describes Samson as a “lifetime Nazirite” (The Jewish Study Bible capitalizes the word in the side notes but not in scripture translation).
Amos 2:11-12 says this:
11 And I raised up of your sons for prophets, and of your young men for Nazirites. Is it not even thus, O ye children of Israel? saith the LORD. 12 But ye gave the Nazirites wine to drink; and commanded the prophets, saying: ‘Prophesy not.’
An entire tractate of the Talmud is dedicated to the topic of the Nazir: