In contrast with the other tractates in Seder Kodashim, which deal with Temple sacrifices, the focus of Massekhet Arakhin is on vows made by individuals for the use and upkeep of the Temple (referred to as bedek ha-bayit – see Sefer Melakhim II, Chapter 12).
When the First Temple stood, it was common for a person who faced a dangerous situation or experienced a joyous occasion to commit to bring a sacrifice as a show of thanksgiving. For similar reasons, a person may have chosen to donate his value to the Temple. Establishing the person’s value in monetary terms can be done in many ways, for example, based on his weight or on the price that he could be sold for in the slave market. Nevertheless, it is impossible to evaluate the worth of a human life in a serious manner. For this reason, the Torah establishes set values for vows such as these, which fluctuate depending on the age and gender of the person (see Vayikra 27:1-7). Vows such as these are called nidrei arakhin. The discussion of the Talmud regarding these laws is the focus of Massekhet Arakhin.
The approach taken by the Sages is that the laws of arakhin are separate from other vows that an individual may take, such as dami alai – “I accept my worth upon me” – where the person intends to contribute his worth to the Temple. In such cases – and it need not be his own worth; it can be the worth of another person or the worth of an animal or any other object – the worth is established based on how much that person would be sold for on the open market. A section of Massekhet Arakhin deals with how such valuation is attained. Such vows are referred to by the Sages as nidrei damim.
These two separate tracks – nidrei arakhin and nidrei damim – are examined in this tractate, and establishing the parallel and separate attributes of each is a central part of Massekhet Arakhin.
Most of the differences between these two types of vows stem from a basic distinction between them. In nidrei damim a person can choose to make a vow about any object based on his own intentions and the worth of that object. In contrast nidrei arakhin are based on a set schedule of valuations that are not related to the actual worth of the person. Thus, a person can take a vow committing to contribute the value of a newborn baby, but since arakhin in the Torah begin at the age of a month, such a vow would have no meaning. On the other hand, someone who takes a vow committing to pay the worth of someone who suffers from a debilitating disease will not have to pay anything if such a person has no market value. The value of such a person based on nidrei arakhin would remain constant.
Another difference is the idea of heseg yad, or the ability to pay. When a person makes an ordinary vow to the Temple, he is obligated to pay and he cannot pay less than he committed. Neither a kohen nor the treasurer of the Temple can offer to free him of his obligation, since he made his pledge to God. In nidrei arakhin, however, the Torah includes a clause that specifically gives the kohen the right to establish the man’s ability to pay (see Vayikra 27:8) so that someone who has limited means will only pay what he can afford.
The differences between these vows notwithstanding, there are also areas of similarity between them that are discussed in this tractate. For example, both of these vows can be brought before a Sage for review if they were made in error. Similarly, in both cases it is the kohen who acts as the representative of the Temple when establishing the value of the vow.
Aside from the discussions about vows, Massekhet Arakhin deals with a number of related topics, including how the Temple collected the donations that had been committed and a unique type of vow – someone who contributes his family’s ancestral lands in Israel to the Temple. In connection with this, the tractate also discusses the general laws regulating the sale of homes and real estate in the Land of Israel.