Arachin, Chapter 3, Mishnah 1. There are areas of halacha in which the Torah does not ask what something is actually worth. Instead it sets a fixed sum, and that sum is paid whether the object of the obligation is worth far more or far less. This entire chapter is devoted to those laws, and arachin, the subject of our masechet, is the first example.
As we learned in the first perek, when a person dedicates his own value to the Beit Hamikdash, or declares the erech of somebody else, the amount he owes is determined by a table in the Torah based on gender and age alone. The individual standing in front of us makes no difference. A fixed sum of that kind will sometimes work out in the donor's favor and sometimes against him, and that is precisely the point our mishnah wishes to make.
The list of fixed payments
"Yesh ba'arachin l'hakel u'l'hachmir": in the halachot of arachin the fixed sum can sometimes come out easier on the one who vowed and sometimes harder on him, all according to the circumstances of the particular case.
"Bisdeh achuza l'hakel u'l'hachmir": redeeming an ancestral field follows the same pattern. A sdeh achuza is farmland in Eretz Yisrael that came down to its present owner from the forefather who received it in the division of the land under Yehoshua bin Nun. Should the owner consecrate it to the Beit Hamikdash, the redemption price is the rate the Torah lays down, and the market value of that particular field is never consulted. So here too the outcome can be favorable or costly.
"B'shor hamu'ad shehemit et ha'eved l'hakel u'l'hachmir": a shor hamu'ad is an ox with a record of goring people three times. Should it gore yet again and this time cause the death of a Cana'ani slave, his master receives thirty sela'im from the ox's owner. That figure is frozen, whatever this slave happened to be worth. Once more, in some cases a kula and in others a chumra.
"B'ones, u'mfateh, u'motzi shem ra": three payments imposed on a man. The ones is one who violated a na'arah, a girl between the ages of twelve and twelve and a half. The mefateh seduced such a girl and she consented. Each of them pays a penalty of fifty sela'im, and her family's social standing plays no role in the figure. The motzi shem ra is a husband who slanders his wife by accusing her of adultery committed during the period between the eirusin and the nisu'in, between the halachic betrothal and the marriage itself. He pays one hundred sela'im, and here as well her standing does not change the sum.
In every one of these cases, because the amount is fixed in advance, the payment can turn out to be a bargain or a burden.
How arachin works out both ways
"Yesh ba'arachin l'hakel u'l'hachmir. Keitzad?" The mishnah now demonstrates its opening claim. How exactly does the erech contain both a leniency and a stringency?
"Echad hama'arich et hana'eh sheb'Yisrael v'et hakaur sheb'Yisrael": the erech is identical whether the person named is the handsomest man in Yisrael, who could command one hundred maneh from a buyer, or the homeliest man in Yisrael, whose price might not reach beyond five sela'im. Provided the man is a male aged twenty to sixty, "noten chamishim sela", the sum owed is fifty sela'im, and no other factor enters the calculation.
Fifty sela'im for a man whose market value is one hundred maneh is a striking leniency. The donor discharges his vow for a fraction of what the man is worth. But fifty sela'im for a man worth five sela'im is a serious stringency. He pays ten times the value of the person he named. One fixed number, two opposite results.
The contrast: "harei damav alai"
"V'im amar harei damav alai, noten et shovyo." Suppose he chose the language of damim rather than erech, obligating himself in this person's monetary worth as a gift to hekdesh. Now he owes exactly what that individual would fetch, the price a purchaser would pay for him in the slave market. Such a sum is measured entirely by the particular person named, and it can land well above fifty sela'im or well below it.
Set the two vows side by side and the mishnah's statement becomes clear. Measured against the vow of damim, which tracks real value, the vow of erech will sometimes cost far less and sometimes far more, all depending on who the person happens to be.