Arachin, Chapter 4, Mishnah 2. This chapter is exploring whose financial situation we look at when a vow is paid, and our mishnah continues directly from the previous one by drawing a comparison to a completely different kind of pledge: sponsoring somebody else's korban.
Recall where the last mishnah left us. A person swore to donate the erech of another individual, and it turns out he does not have the means to pay that amount. We do not look at the net worth of the person whose erech was pledged. We evaluate the finances of the one who opened his mouth and made the vow, and he pays according to what he can afford. The subject of the vow is simply irrelevant to the calculation.
A Person Can Sponsor Someone Else's Korban
Our mishnah now sets that halachah alongside a parallel situation. A person is permitted to declare that he will bring a korban that somebody else is obligated to bring. Once he makes such a declaration he must supply that korban, and the original obligated party has his own obligation discharged through the donated offering.
In the vast majority of cases this raises no question at all, because korbanot are fixed. The same offering is brought by the wealthiest and the poorest Jew alike. There are, however, korbanot that are calibrated to a person's means. The classic example is the metzora, one afflicted with the skin condition of tzara'at. A metzora who has money brings three lambs as part of his purification. A metzora who is poor is permitted to substitute two turtledoves or two young pigeons in place of two of those lambs.
Now consider a rich man who takes upon himself the offering owed by a metzora of very limited means, and then the mirror image: a man with nothing who undertakes the offering owed by a metzora of substantial wealth. Which of the two men determines what gets brought to the Beit Hamikdash?
The Words of the Mishnah
The mishnah states: "Aval bekorbanot eino chen." With arachin, as we learned, the finances of the one making the vow are what determine the sum he pays. With korbanot the rule does not work that way.
The case is introduced with the words "Harei she'amar", here is one who declares, and his declaration reads "korbano shel metzora zeh" (the offering belonging to this metzora) "alai" (falls upon me). Should that metzora be a man of no means, "im haya metzora ani", then what the declarer must supply is "mevi korban ani", the offering of the poor, and it changes nothing that the declarer himself is well off. Should the metzora be a man of means, "ashir", the ruling is "mevi korban ashir": the full three lambs of a wealthy man must be produced, and the declarer's own empty pockets do not reduce the requirement.
The principle emerging from the Tanna Kamma is that with korbanot we do not measure the sponsor at all. We measure the person who carries the underlying obligation.
Rebbi Objects to the Contrast
Rebbi now steps in. He is not disputing any of the rulings. He accepts every halachah exactly as stated. What he rejects is the sweeping generalization, the framing that presents arachin and korbanot as two opposing systems. To his mind that contrast does not hold up logically. The two areas of halachah are not built on opposite foundations at all; the cases simply differ from one another.
"Omer ani, af be'arachin ken." Rebbi says: in arachin the very same principle applies. Nothing separates arachin from korbanot in essence. The laws of arachin only appear different because the scenario under discussion is different.
Rebbi presses his point with a question. "Vechi mipnei mah", for what reason does the case of "ani shehe'erich et he'ashir", a pauper who pledged the valuation of a man of wealth, come out as "noten erech ani", payment at the pauper's rate? Superficially it seems that we are following the mouth that spoke, which would put arachin and korbanot on opposite tracks. Rebbi's resolution: "She'ein he'ashir chayav klum", the wealthy man named in that vow bears no liability at all toward the Beit Hamikdash. He obligated himself in nothing whatsoever. The entire debt came into being through the pauper's words. Having manufactured the liability, he owns it, and it is therefore his own means that fix its size.
And in the korban case the logic runs the same way. We are not saying that we peer at some outside party instead of the one who vowed. What the sponsor did was attach himself to the metzora's already existing obligation. He grabbed hold of a debt that was sitting there waiting to be paid, and he now stands responsible for precisely what the metzora was responsible for. In both areas we follow the person who owns the obligation. In arachin the vower created the obligation himself, so we follow him. In korbanot he latched onto a preexisting obligation belonging to someone else, so we follow that other person.
The Matching Case in Arachin
Rebbi backs this up by producing the arachin case that lines up precisely with the korban case. "Aval he'ashir she'amar", take a wealthy man who announces "erki alai", my own valuation is upon me. "Veshama he'ani": a pauper standing nearby catches the declaration, "ve'amar", and responds with the words "mah she'amar zeh alai", whatever this man has just obligated himself in is now mine to pay. The ruling is "noten erech ashir": the pauper hands over a wealthy man's valuation.
This is the exact analogue of the korban case. Here the poor man is not generating a new obligation out of his own mouth. He is fastening himself to an obligation that already existed, the wealthy man's own pledge. Just as the poor sponsor of a wealthy metzora's korban takes hold of the metzora's standing debt, so too here the poor man must produce whatever the wealthy man was already bound to produce. Same principle, same result, in both areas of halachah.
When the Vower's Wealth Changes
The mishnah's final clauses take up the man whose circumstances shift between the vow and the payment. "Haya ani vehe'eshir": he was destitute when he spoke and had come into money by the time the debt was collected. "O ashir vehe'eni": or the reverse, he spoke as a man of wealth and had lost it all by the time payment was demanded. In each of these the ruling is "noten erech ashir", he is assessed at the wealthy man's full rate.
The rule is that a person does not receive the reduced rate of a poor man unless he is poor both at the moment he makes the vow and at the moment he pays. In the first case he was poor when he spoke but wealthy when payment came due, so he pays the higher figure. In the second case he was wealthy when he spoke, so even though poverty overtook him afterward, the pledge was formed in wealth and the full amount stands.
A stricter opinion follows. "Rebbi Yehudah omer": take even the case of "afilu ani vehe'eshir", a man who vowed while destitute and then prospered, and after that "vechazar vehe'eni", sank back down into poverty before ever handing over the money. The ruling is still "noten erech ashir". For Rebbi Yehudah the reduced assessment is granted only where the poverty never lifted from the moment the words left his mouth until the moment of payment; a single stretch of prosperity anywhere in between forfeits the concession altogether.