Arachin, Chapter 5, Mishnah 1. So far the masechet has treated the Torah's fixed valuations and vows based on a person's market price. Now a fresh category of pledge comes before us: someone who consecrates to the Beit Hamikdash an amount corresponding to his own weight, or to the weight of one of his limbs. The Mishnah first clarifies which commodity he becomes liable for, and then faces a practical obstacle: how can a limb still joined to a living body be placed on a scale?
Pledging one's weight
"Ha'omer mishkali alai, noten mishkalo": someone who declares, "my weight is upon me," thereby taking on an obligation to consecrate his own weight, must hand over that weight in whatever commodity he specified. The Mishnah spells this out: "im kesef, kesef", should silver have been named, silver is what he delivers, and "im zahav, zahav", should the vow have mentioned gold, gold is what he owes.
And if he named no substance at all? Then he may discharge his vow with anything that is ordinarily sold by weight, even the least valuable such item. The Gemara illustrates the point with produce: if in his town onions are sold by weight, he may satisfy his pledge with his weight in onions.
There is, however, an important qualification. A person's own standing interprets his words. If the one who took the vow is very wealthy, we assume as a matter of course that he had gold in mind, even though he never said so, and he is held to gold.
The mother of Yirmatya
The mother of Yirmatya
To illustrate the principle the Mishnah records an incident: "Ma'aseh be'ima shel Yirmatya", a case involving the mother of a girl named Yirmatya, "she'amra: mishkal biti alai", who declared that her daughter's weight was incumbent upon her. The chachamim supply the background. The child had fallen sick, and her mother undertook that if she recovered, an amount matching the girl's weight would go to hekdesh. No commodity was named in the vow at all.
"Ve'alta liYerushalayim ushkaluha venatna mishkala zahav": she came up to Yerushalayim, they placed the girl on the scale, and she paid the girl's weight in gold. Although her vow contained no specification whatsoever, since she was a woman of means the chachamim understood her intention to have been gold, and that is what she was required to give.
Pledging the weight of a limb
Pledging the weight of a limb
Attention now shifts to a person who consecrates what one of his limbs weighs, and this raises a genuine complication. So long as a limb remains part of a living body, one cannot lay it on a scale and simply read the number. Should he lean into it, the reading exceeds the truth; should he lift it slightly or let something bear it, the reading falls short. No honest figure can be obtained by direct weighing, so the chachamim are obliged to devise a procedure.
"Mishkal yadi alai": one says, "the weight of my arm is upon me." How is that weight determined?
Rabbi Yehuda's method
Rabbi Yehuda's method
The first opinion is that of "Rabbi Yehuda", who says: "memaleh chavit mayim", one takes a barrel and fills it with water right to the rim, "umachnisa ad marpeko", and lowers the limb in as far as the elbow joint. Whatever water overflows matches the arm's volume precisely. He then draws the arm out, leaving the barrel deficient by exactly that much water.
"Veshokel basar chamor vegiddin va'atzamot": he takes the flesh of a donkey together with its sinews and bones. Donkey flesh is comparable in density to human flesh, and since an arm is not flesh alone but flesh, sinews and bones, and each of these has its own density, all three components must be included in the substitute.
"Venoten letocha ad shetitmaleh": donkey tissue is added piece by piece until the water climbs once more to the rim of the barrel. What has now been placed inside occupies the same bulk as the arm did. That material is taken out and weighed, and the resulting figure is treated as the arm's weight, which is the sum he owes to hekdesh.
Rabbi Yose's objection
Rabbi Yose's objection
"Amar Rabbi Yose": he disputes the entire technique. "Vechi heich efshar", how can such a thing be accomplished, asks Rabbi Yose, "lechaven basar keneged basar", to line flesh up against flesh, "va'atzamot keneged atzamot", bone against bone? Equalizing the overall bulk presents no difficulty, but the inner proportions will inevitably diverge. A man is not a donkey, and the makeup of the two limbs is not the same. The donkey's material may hold a greater share of bone than the human limb does, and a given volume of bone and of flesh do not weigh alike. Once the ratio is skewed, so is the number on the scale, and the one who vowed hands over either too much or too little.
"Ella shamin et hayad", rather, the limb is appraised, "kama hi re'uyah lishkol", meaning how much a limb of this sort should be expected to weigh. Rabbi Yose thus abandons measurement entirely: no immersing of the arm, no weighing of donkey tissue. The assessment is made by expert estimation, and the sum arrived at is what he delivers in whatever commodity his vow named.