נזיר

Shmuel said: Whoever sits in observance of a fast is called a sinner, as it is inappropriate to take unnecessary suffering upon oneself. The Gemara comments: Shmuel holds in accordance with the opinion of the following tanna, as it is taught in a baraita: Rabbi Elazar HaKappar the Great says: What is the meaning when the verse states, with regard to a nazirite: “And he will atone for him for that he sinned by the soul [nefesh]” (Numbers 6:11). But with what soul did this nazirite sin? Rather, the nazirite sinned by the distress he caused himself when he abstained from wine, in accordance with the terms of his vow. And are these matters not inferred a fortiori? And if this nazirite, who distressed himself by abstaining only from wine, is nevertheless called a sinner and requires atonement, then with regard to one who distresses himself by abstaining from each and every matter of food and drink when he fasts, all the more so should he be considered a sinner.

Conversely, Rabbi Elazar says: One who accepts a fast upon himself is called sacred, as it is stated with regard to the nazirite: “He shall be sacred, he shall let the locks of the hair of his head grow long” (Numbers 6:5). Here too, one can apply an a fortiori inference: And if this nazirite, who distressed himself by abstaining from only one matter, wine, is nevertheless called sacred, then with regard to one who distresses himself by abstaining from every matter, all the more so should he be considered sacred. The Gemara asks: And according to the opinion of Shmuel, the nazirite is indeed called sacred, as stated by Rabbi Elazar.

(1) A person might say, "Since envy, desire, [the pursuit] of honor, and the like, are a wrong path and drive a person from the world, I shall separate from them to a very great degree and move away from them to the opposite extreme." For example, he will not eat meat, nor drink wine, nor live in a pleasant home, nor wear fine clothing, but, rather, [wear] sackcloth and coarse wool and the like - just as the pagan priests do.
This, too, is a bad path and it is forbidden to walk upon it. Whoever follows this path is called a sinner [as implied by Numbers 6:11's] statement concerning a nazarite: "and he [the priest] shall make an atonement for him, for his having sinned regarding [his] soul." Our sages declared: If the nazarite who abstained only from wine requires atonement, how much more so does one who abstains from everything.
Therefore, our Sages directed man to abstain only from those things which the Torah denies him and not to forbid himself permitted things by vows and oaths [of abstention]. Thus, our Sages stated: Are not those things which the Torah has prohibited sufficient for you that you must forbid additional things to yourself?
This general statement also refers to those who fast constantly. They are not following a good path, [for] our Sages have forbidden a man to mortify himself by fasting. Of all the above, and their like, Solomon directed and said: "Do not be overly righteous and do not be overly clever; why make yourself desolate?" (Ecclesiastes 7:16 .