Arakhin 19B

״רוחבו״ מהו? ״ישיבתו״ מהו? ״עוביו״ מהו? ״היקיפו״ מהו? תיקו.

If one vowed that it is incumbent upon him to donate his width, what is the halakha? Likewise, if one vowed to donate his sitting, what is the halakha? If he referred to his thickness, what is the halakha? Finally, if he spoke of his girth, what is the halakha? The Talmud states that these dilemmas should stand unresolved.

משקל ידי עלי וכו׳. תנו רבנן: ״משקל ידי״ ו״משקל רגלי עלי״, רבי יהודה אומר: מביא חבית וממלא מים, ומכניס ביד עד האציל, וברגל עד הארכובה.

§ The Mishnah teaches that there is a dispute between R' Yehuda and R' Yosei concerning one who says: It is incumbent upon me to donate the weight of my forearm, as to how he ascertains the weight of his forearm. A baraita states this dispute in greater detail in a baraita (Tosefta 3:2): With regard to one who says: It is incumbent upon me to donate the weight of my forearm, and with regard to one who says: It is incumbent upon me to donate the weight of my leg, R' Yehuda says: He brings a jug and fills it with water, and he inserts his forearm up to the elbow or his leg up to the knee, into the water.

ושוקל בשר חמור גידים ועצמות, ונותן לתוכה עד שתתמלא, ואף על פי שאין ראיה לדבר, זכר לדבר, שנאמר: ״אשר בשר חמורים בשרם״.

And in order to measure the displacement, he weighs donkey flesh, sinews, and bones, and places it into the jug until it fills, and the water reaches the same level as it was when his arm or leg was inserted. And even though there is no proof for the matter, that donkey flesh weighs the same as human flesh, nevertheless there is an allusion to the matter, as it is stated: “Whose flesh is as the flesh of donkeys” (Ezekiel 23:20).