A summary of a shiur kelali delivered by HaRav Aharon Lichtenstein שליט"א.

When two shutafim are splitting a chatzer, says the mishnah (Bava Batra 2a), one may force the other to build the wall between their portions with the materials that are customarily used in their community ("hakol keminhag hamedinah"). The Gemara, after determining that the mishnah refers not to a chatzer which the shutafim were required by the halakhah to split, but to one which they simply agreed to split, asks:

במאי אוקימתא למתניתין - בשאין בה דין חלוקה. אי בשאין בה דין חלוקה, כי רצו מאי הוי? נהדרו בהו! א"ר אסי א"ר יוחנן שקנו מידן. וכי קנו מידן מאי הוי? קנין דברים בעלמא הוא!

We have established that the mishnah is discussing a case where there was no requirement to split. If so, then why does it matter that they wanted to split? Let them change their minds! [That is, why should the fact that they agreed to split be enough to require them to follow the local custom? Why can't the one who does not want to follow it simply decide not to split the chatzer after all?] R. Asi said in the name of R. Yochanan: The mishnah is referring to a case where the shutafim made a kinyan chalippin to finalize the agreement. [Asks the Gemara:] Why does it matter that they made a kinyan? It's only a kinyan devarim!

The Gemara here maintains that a kinyan made regarding a verbal agreement to do something in the future (a "kinyan devarim") is invalid, as opposed to one that represents a present transaction, which is valid. The kinyan does not legally obligate the participants to keep their word.

It is important to note that creating a financial obligation on oneself is possible and is not considered a kinyan devarim. If Reuven says to Shimon, "I am hereby indebted to you 100 maneh" - "הריני חייב לך מאה מנה" - and they make a kinyan, Reuven is indeed obligated to pay the money; that is not an agreement to do something in the future - it is the creation of a debt which exists immediately.

What, then, is lacking in a kinyan devarim? 1) The simplest explanation, and the one which is assumed by most rishonim, is that there is nothing on which a kinyan devarim can take effect. No transaction is occurring; no `iskah, no business deal of any import, is transpiring at this point in time. The deficiency is not in the kinyan per se, but in what the kinyan is attempting to accomplish. Rashi on our Gemara seems to understand kinyan devarim in this manner; the Rambam (Hilkhot Mekhirah 5:14) does so explicitly: "A kinyan does not work on things which have no substance" -

2) Alternately, we could understand that although the lack of a transaction at the time of the kinyan does not theoretically remove this deal from the realm of kinyanim, it does, from a practical perspective, remove the possibility of kinyan, because there is nothing to which the ma`aseh kinyan - the act which triggers the kinyan - can relate. A ma`aseh kinyan must be aimed at some significant transaction.

3) The Rif (She'elot Uteshuvot siman 14) compares, even equates, asmakhta[2] and kinyan devarim. As in asmakhta, in cases of kinyan devarim an agreement about the future is made (albeit not a conditional one). When an agreement refers only to the future, says the Rif, we can not assume that there was gemirat da`at (full conviction), and the kinyan does not bind the parties.

If a man says, "If my wife bore a son, he may take a maneh," and his wife bore a son, the son is entitled to the maneh (mishnah Bava Batra 140b). Why is this statement of the father binding? The Rashbam (ibid.) does not seem to consider this halakhah problematic. The Ri Migash, however, says that the mishnah must be referring to a shekhiv mera`.[3] The mishnah could not be referring to a healthy person because, among other things, the man's statement is a kinyan devarim and an asmakhta, and therefore not binding. According to the Ri Migash, then, even though this case falls into the category of kinyan devarim, if the person is a shekhiv mera` then there is no problem. The Rashba rejects the Ri Migash, because, he says, there is no difference between a shekhiv mera` and a healthy person when the problematic aspect of the kinyan is that the transaction is not real enough ("בדבר שאין לו גוף"), as is the case in kinyan devarim. He also disproves the Ri Migash from a Gemara (147b-148a) which says: מילתא דאיתא בבריא איתא בשכיב מרע; דליתא בבריא ליתא בשכיב מרע. I.e., the only difference between a shekhiv mera` and a healthy person is regarding the ma`aseh kinyan; regarding the entities on which their kinyanim work, they are the same.

While the Rashba's proof from the Gemara seems convincing, we can at least find a logical basis for the Ri Migash. How does divrei shekhiv mera` kikhtuvin vekhimsurin damu work? 1) One might contend that it works as a regular matanah; Chazal simply gave a shekhiv mera` the power to effect a matanah with speech alone. 2) Alternately, it works as a special channel of yerushah; because of the shekhiv mera`'s verbal statement, miderabbanan the person to whom he assigned the gift receives it as an inheritance. The effect of the statement, then, is to appoint the recipient a beneficiary; after that is done, the money changes hands automatically. If matenat shekhiv mera` works as a matanah, then presumably the normal requirements of matanah (other than the ma`aseh, which is the shekhiv mera`'s dispensation) remain. If, however, it works as a yerushah, then the rules may be completely different; appointing an heir is a process altogether different from giving a gift. The Rashba apparently believes that possibility #1 is correct, and therefore does not see any reason why shekhiv mera` should be any different from a healthy person regarding kinyan devarim and asmakhta; kinyan devarim should not work for any person. The Ri Migash, however, may prefer possibility #2. If so, perhaps a lower level of da`at is required to appoint a yoresh than to effect a matanah, and therefore asmakhta is not problematic here; even though in asmakhta there is not total gemirat da`at, the da`at that does exist is sufficient in the realm of shekhiv mera`, which after all is only a form of yerushah. Then, if we assume that the Ri Migash understands that the problem with kinyan devarim as well is that there is a lack of gemirat da`at (parallel to asmakhta), his allowance of kinyan devarim in cases of shekhiv mera` is understood as well.[4]

We could also understand the Ri Migash according to the second explanation given above for kinyan devarim (that it does not work because the ma`aseh kinyan has nothing to which to attach itself). The ma`aseh kinyan is exactly from what a shekhiv mera` is exempt; his matanah works even though there is no ma`aseh. So, he can make a binding agreement even in a case of kinyan devarim.

What types of cases are considered kinyan devarim? The only explicit case is the agreement to split a chatzer (Bava Batra 3a). The Rambam (Hilkhot Mekhirah 5:14) includes other contracts to do something in the future, e.g., to create a business partnership.

The Gemara (Bava Metzi`a 10a) says that a po`el, a hired worker, may quit at any time, even if he agreed to work for longer, because "לי בני ישראל עבדים - ולא עבדים לעבדים." The Shakh (Choshen Mishpat 333:14) suggests two explanations: 1) Even though the kinyan which finalized the agreement does work, the worker can quit anyway, because of the special privilege granted by the pasuk. 2) The kinyan is ineffective, because it is a kinyan devarim. The Machaneh Efrayim (Hilkhot Sekhirut Po`alim siman 1) raises a fundamental question about sekhirut po`alim: Does the employer acquire the worker's labor itself, or does he acquire rights in the worker himself to the labor that he does? The Rambam (see Hilkhot Mekhirah 13:15) clearly affirms the latter. According to the Rambam, the second explanation of the Shakh falls away - sekhirut po`alim is not a kiny devarim, because it involves not an agreement for the future but a acquisition of rights in the worker.

If a person says to another, "On day x I will give you y amount of money," and they make a kinyan over the agreement, is it binding? This case, called קנין אֶתֵן, is a borderline kinyan devarim; on the one hand, it seems like an agreement to do something in the future, but on the other hand, it involves a form of indebtedness, and, as we said at the beginning, if someone says "הריני חייב לך מאה מנה", he is obligated to pay. The `Ittur (Ma'amar 2 "Kinyan") quotes an opinion that kinyan eten is a kinyan devarim; the Ba`al Ha`ittur himself disagrees. To get a better understanding of what is at issue here, we will digress for a moment to a completely different realm, that of nedarim.

The Torah (Devarim 23:22) states "כי תדור נדר לה' א-להיך לא תאחר לשלמו". The Gemara applies this prohibition to numerous cases, including nezirut; if someone accepts nezirut upon himself, and three regalim (which constitute "lateness" or "delay" in this halakhic context) pass before he fulfills this obligation, then he has transgressed bal te'acher. Regarding shevu`ah, however, there is no bal te'acher; if someone swore to perform a certain act, and then did not do it for three regalim, he has not violated any prohibition. What is the difference between nezirut and shevu`ah? Bal te'acher applies to a chov, a debt, but not to a chiyyuv, an obligation. (Note the language of the pasuk, "Lo te'acher leshalmo.") One who has promised a nezirut is now indebted to God; he as it were owes Him that period of perishut and kedushah. Fulfilling a shevu`ah, on the other hand, is more like a kiyyum mitzvah; one is obligated to at some point in the future perform the act, but in the meantime there is no indebtedness.

The distinction between chov and chiyyuv is exactly what is at issue regarding kinyan devarim, and especially kinyan eten, as well. An agreement to do some act in the future is comparable to a shevu`ah - only a chiyyuv is created, not a chov; a kinyan made over such an agreement is a kinyan devarim and is not binding. On the other hand, "הריני חייב לך מאה מנה" creates a chov, a state of indebtedness. The question about kinyan eten, then, is how to view the agreement. Is "אתן לך מאה מנה ביום פלוני" simply a promise to perform a future act, i.e., handing over the money on the stated day, or does it create a debt? The opinion quoted in the `Ittur apparently held the former, and therefore treats kinyan eten as a kinyan devarim, while the Ba`al Ha`ittur himself apparently held the latter.

[1] Note that the lack of "substance" here is different from that which the Rambam mentions in chapter 22; there he refers to things which are intangible, such as smells and tastes, which are also not subject to kinyan.

[2] An asmakhta, discussed in numerous instances in the Gemara, is an obligation a person accepts believing that he will never have to fulfill it. One example is in the mishnah on Bava Batra 168a. In that case, a debtor paid back part of his debt, and, to avoid having to write a new shetar on the remaining amount, he and his creditor agreed to give the original shetar to a mutually trusted third party (a "shelish") with the understanding that only part of the debt remained. Believing he would make payment, the debtor then said to the shelish that if by day x he has not paid back the remaining amount, he (the shelish) should give the shetar back to the lender, even though the lender would then be able to collect the entire debt again. If day x arrives and the borrower has not paid, then according to R. Yosi the shelish should hand over the shetar, and according to R. Yehudah he should not. The Gemara there explains that the debate revolves around asmakhta; R. Yosi holds asmakhta kanya, and R. Yehudah holds asmakhta lo kanya. R. Yehudah's logic is that since the person thought that he would never have to actually fulfill the obligation that he accepted, there was no gemirat da`at and the agreement is not binding.

[3] A shekhiv mera` is a person who is about to die. There is a special halakhic dispensation, which is miderabbanan according to the conclusion of the Gemara on Bava Batra 147b, allowing a shekhiv mera` to give gifts without the usually required ma`asei kinyan, simply by stating his desires - "divrei shekhiv mera` kikhtuvin vekhimsurin damu."

[4] The Remah (Yad Ramah chapter 9 siman 3), like the Ri Migash, says that the mishnah on 140b refers to a shekhiv mera`, because otherwise there would be a problem of asmakhta (he does not mention kinyan devarim). He gives two alternative explanations why asmakhta works for a shekhiv mera`, neither of which assumes that matenat shekhiv mera` requires any less da`at than regular transactions: 1) Someone who is about to die usually is in a very serious mood, and does not make flippant statements. So, even though normally such a statement would be an asmakhta, reflecting lack of conviction, in a case of shekhiv mera` it is not - we can assume that there indeed was complete gemirat da`at. 2) Generally, asmakhta lo kanya only as long as the money has not changed hands; once the payment has been made, the makneh can not take back his money based on the claim that the agreement was an asmakhta. So, since divrei shekhiv mera` kikhtuvin vekhimsurin damu, i.e., we consider as if the gift has been given, the statement is binding even according to general asmakhta rules.