Avot193

12:

Vows are a fence around asceticism: despite what one might think, the sages disapproved of rampant asceticism. Since often vows were taken by people in a moment of emotion when they vowed to 'give up' something or other the sages were concerned that this not be taken to extremes. The rules and regulations that surround the taking of vows upon oneself serve to limit the possibilities and, even all else fails, to facilitate their abrogation where possible.

13:
The most obvious example of a vow of abnegation is that of the Nazirite. The basic details are given in the Torah [Numbers 6:1-6]:

In every culture there are people who feel that they must deprive themselves of some of the good things of life: possessions, society, sex and so forth. Medieval monasticism is a good example, where people took vows of 'poverty, chastity and obedience' – in other words, they vowed to deprive themselves of possessions, sex and independence.

14:
However, in the provisions of the Torah we find that there are already restrictions 'built in'. The Nazirite may only deprive himself of three things (consumption of alcohol, cutting of hair and contact with a corpse) and that only for a certain period of time. When the time is up the vow is terminated. The Torah [Numbers 6:13-18] prescribes as follows:

because the vows have been terminated. Most interestingly, elsewhere in that same chapter [Numbers 6:11] we read that

15:
Perhaps the most cogent argument against such behaviour is offered by Rambam in his Mishneh Torah [De'ot 3:1], where he says:

To be continued.

In Avot 191 we mentioned the lex talionis – 'an eye for an eye'. Jacob Chinitz writes (my own comments are indicated within the text):

While in most texts about eye for eye, your explanation about deliberate rabbinic altering of the pshat [plain meaning of the text] is necessary, in one case – in [parashat] Emor [Leviticus 24:18] – the text itself would lean towards a non-literal interpretation. It says: Makei Behema Yeshalmena, Nefesh Tachat Nefesh [one who strikes an animal shall make restitution, a life for a life]. No one would insist that this is to be taken literally. No one would say this means we kill the killer of the animal, or that we kill his animal in retaliation. It is an expression meaning payment. Especially since the word Yeshalmena is used. Why not extend this to Ayin Tachat Ayin [an eye for an eye]? Makei Ish … Mot Yumat, Umakei Behema Yeshalmena. Obviously the Torah is making a distinction between Tashlum, which is compensation by money, and Mot Yumat [death], which is not payment but punishment. This is the difference between civil and criminal law. Civil law compensates. Criminal law punishes. Why should we insist that Ayin Tachat Ayin is literal, and means punishment, and not as a metaphor, meaning compensation. Yeshalmena, make it whole, pay. In Makei Ish it does not say, Yeshalem Nefesh Tachat Nefesh, but Mot Yomat, which punishment and not compensation.

I respond:

I must confess that I do not fully understand what is worrying Jacob. We have already established that the sages did not understand 'an eye for an eye' literally. Furthermore, in Exodus 21:29 they even interpreted the word yumat [he shall be killed] as indicating monetary compensation. However, Jacob's main point is well taken.