Which items may be acquired through kinyan chalipin?
One of the easiest and most popular ways to effect a kinyan is to perform chalipin. The classic payment kinyan known as a kinyan kesef has severe limitations. Though it functions for land transactions, Chazal invalidated kinyan kesef for acquiring portable items, since it doesn't actually transfer the acquired item to the location of the purchaser. Such a condition - when an item already purchased has yet to be delivered - is hazardous since, in the event of potential damage, the seller will feel little compunction to rescue an item which is no longer legally his. Hence, the Chakhamim invalidated this form of kinyan and instead required some form of actual transfer (meshikha - pulling into your house, or hagbaha - raising the item 3 tefachim are the most common forms).
There is, however, one method of legally transferring items without actually relocating them. This is known as kinyan chalipin - a transaction which doesn't involve (and cannot involve) currency. Instead, two items are bartered for each other with the emphasis upon the utility each will derive rather than the respective worths. Once Reuven delivers his item to Shimon, he automatically receives possession of Shimon's item even if it is in a different location and no action is directly performed to it. Though it resembles kinyan kesef (insofar as an item is deposited to acquire a second item) its effectiveness far exceeds kesef. Paying money does not accomplish a kinyan until actual meshikha is performed; by contrast, chalipin works immediately.
The gemara cites a fundamental dispute regarding the technique of this kinyan chalipin. Which items can be delivered as the initial exchange in order to acquire items which are not present? In part, this question stems from the biblical source of chalipin. This source can be found in a verse in Ruth 4:7 which describes the manner by which Bo'az redeemed land from the Go'el. The pasuk describes Bo'az removing his shoe and handing it to the Go'el in exchange for land. Historically then, the first recorded chalipin was performed with a shoe – an example of what in Halakha is known as a 'kli.' As opposed to an amorphous and utility-less matter, a kli is an item with a specific shape and a consequent function. Loosely translated we might refer to it as a utensil (though articles of clothing and anything else with specific function qualify as well). Must all consequent chalipins be performed with such a kli or can chalipin be performed with any matter? This forms the nucleus of a machloket between Rav Nachman and Rav Sheshet cited by the gemara in Bava Metzia (47a). Rav Nachman takes the literal approach, insisting that chalipin precisely mirror the original model. Rav Sheshet agrees that chalipin should resemble that original form but does not insist upon the exact format. Instead, it suffices to use a complete item; for example, according to Rav Sheshet, fruit may be bartered as long as a complete item is rendered. Half fruits (or for that matter any other item which is not whole) cannot be used, for it then loses any resemblance to that original shoe of Bo'az.
Logically, the place to begin is Rav Nachman. The condition mandated by Rav Sheshet seems plausible enough. Some minimal degree of correspondence between our chalipin and Bo'az should exist. In addition, from a logical standpoint any exchange struck over half fruits might seem ridiculous. However, once the basic integrity of the item exchanged has been assured why should anything more be required? What drives Rav Nachman to demand keilim (plural of kli)?
To help answer the question of why Rav Nachman insisted upon a kli we might pose a related question: WHAT, in fact, did Rav Nachman demand? Was he truly insisting upon utensils or was he concerned with another factor relative to chalipin which GENERALLY exists only in the case of keilim? Rav Nachman might have demanded that only significant items be exchanged, accenting keilim as the paradigm of halakhic significance. Whereas Rav Sheshet merely excluded items which were trivial (half fruits) and extended chalipin to cover all general items, Rav Nachman might have demanded a higher level of 'chashivut' (significance) in order to drive kinyan chalipin.
This option - that Rav Nachman by mentioning kli was merely suggesting items of higher importance - emerges from a study of several adjacent gemarot in Bava Metzia. A reading of Bava Metzia (47a) might indeed suggest that Rav Nachman specifically required utensils. However, the surrounding gemarot provide a somewhat different impression. Several of the gemarot (45-47) as well as the mishna in Kiddushin (28a) suggest chalipin performed with animals. Ostensibly, these items would be disqualified from chalipin according to Rav Nachman because they are not utensils in the true sense. Yet, these gemarot do not indicate Rav Nachman's disagreement; it would seem that Rav Nachman himself might validate these forms of chalipin.
In addition, the gemara in Bava Metzia (45b) disqualifies chalipin with currency for alternate reasons. Ostensibly, according to Rav Nachman, currency should be disqualified since it isn't a utensil!!
There are two basic approaches to this seeming contradiction. Many choose to retain Rav Nachman's position in the strict sense and limit his chalipin to actual utensils. For example, the Ba'al Ha-ma'or claims that Rav Nachman would indeed reject all these instances of chalipin. Though maintaining the inner integrity of Rav Nachman's stance, it forces a rejection of several gemarot. Tosafot take a similar defense of Rav Nachman. They effectively redefine currency and animals as utensils. This definition is strained, since we rarely notice this broader definition of keilim in a universal sense. For example, an animal will not receive tum'a, unlike a true utensil which will. Similarly, classifying a coin as a tool (since, for example, one might choose to use it as ornament) seems to strain excessively the definition of coin.
The Ramban chooses a different route. Indeed, Rav Nachman never intended to limit chalipin to utensils, but instead demanded that chalipin be performed upon SIGNIFICANT items of which utensils are a prime example. One cannot deny that both animals as well as currency - though not keilim in the classic sense - are more significant than foodstuffs. Rav Nachman would accept chalipin on these items not because they are formally defined as keilim but because they are considered meaningful and important items.
We have presented the machloket between Rav Nachman and Rav Sheshet regarding the items upon which chalipin should be performed. Having suggested the logical rationale for Rav Sheshet's position, we then questioned Rav Nachman's view. To understand the motive, we inspected the requirement Rav Nachman installed, and whether it pertained specifically to keilim or rather applied in general to items of significance of which keilim are merely the prototype.
An additional means of inspecting Rav Nachman's position would be to locate instances in which Rav Nachman might even reject genuine keilim for chalipin. Would the official status as keilim be enough to assure successful chalipin or would something additional be required? For example, the gemara in Bava Metzia (47b) eliminates chalipin involving 'meroka' keilim. Rashi claims that this refers to utensils made from animal waste (ancient cultures made use of this refuge; on a winter night as you drive to the Yeshiva you might still smell local Arabs burning this excrement as fuel). The Ritva disagrees with Rashi since in his opinion such utensils are not so repugnant as to prevent people from using them. Instead, he interprets meroka as utensils used to carry urine (the ancient equivalent of a bedpan). This, he claims, is so revolting that chalipin cannot be performed with it. Essentially, both Rashi and the Ritva explained the exception of meroka based upon its disgusting nature, one which strips these utensils of any value or significance. In Rashi's and the Ritva's explanations, then, we note an interesting phenomenon - items which are formally defined as keilim, yet excluded from chalipin even according to Rav Nachman simply because they lack importance. (It might be said that their nature prevents classification as significant items.) We certainly can't prove that Rav Nachman ONLY required significant items (as the Ramban suggested by claiming that Rav Nachman would validate chalipin with animals); we certainly witness, however, that Rav Nachman demands significance AS WELL. Mere formal definition as keilim does not suffice.
A second example of utensils which might still be disqualified from chalipin since they are not important might be keilim which are assur be-hana'a (prohibited to derive benefit from). The gemara (47b) similarly excludes these keilim from chalipin even according to Rav Nachman - even though they might contain the formal status of utensils. Might we similarly conclude that Rav Nachman demands significant items for chalipin and that items which are forbidden are not important since they can't actually be utilized? The Avnei Milu'im suggested an alternative explanation for Rav Nachman's excluding issurei hana'a. He claimed (part of a famous machloket between the Avnei Milu'im and Rav Chayim) that items which are assur be-hana'a are also not OWNED by anyone. Formal ownership is rendered meaningless if the owner cannot actually benefit from his item. Hence, chalipin cannot be performed on items forbidden for benefit because they are not owned, and therefore cannot be halakhically transferred to effect a valid exchange.
We have inspected both angles of Rav Nachman's position. We witnessed that he possibly validated chalipin on animals and only disqualified currency for secondary reasons - not because they aren't officially considered keilim. Alternatively, we located two cases of authentic keilim for all halakhic purposes (meroka and issurei hana'a) which Rav Nachman disqualifies for chalipin. These examples helped us crystallize two very different images of Rav Nachman's chalipin. Either it is limited strictly to formal keilim or it can only be performed upon highly important items – of which keilim are generally (but not always) the primary example.
Having described WHAT Rav Nachman required we can now appreciate the essence of his halakha. If his requirement centers around keilim he might have viewed chalipin as a bartering of utility, as opposed to money-based purchases of more general items which are driven by value exchanges. Hence, only utensils which provide utility may be bartered. Any other item regardless of how important it might be, cannot be exchanged through chalipin. Alternatively, if Rav Nachman did not insist upon utensils per se, but rather upon significant items, we certainly achieve a broader vision of chalipin and do not limit it exclusively to items of utility. Yet, we would still be forced to question why only items of high importance or significance may be bartered.
1. When trying to isolate whether a halakha stems from 'a' or 'b' locate cases where 'a' applies and 'b' doesn't as well as cases where 'b' applies but 'a' does not. In trying to decide whether Rav Nachman emphasized keilim or significant items explore significant items which might not be keilim (animals and currency) as well as keilim which are not significant (meroka and issurei hana'a) .
2) In trying to understand a position first define it. In trying to understand why Rav Nachman makes his demands, first explore precisely what his demands were.